Rules with NIST-800-171 Reference in Guide to the Secure Configuration of Oracle Linux 7

Mapping | Rule Title | Description | Rationale
3.1.1 3.1.5 | Restrict Virtual Console Root Logins | To restrict root logins through the (deprecated) virtual console devices, ensure lines of this form do not appear in `/etc/securetty`:
    vc/1
    vc/2
    vc/3
    vc/4
| Preventing direct root login to virtual console devices helps ensure accountability for actions taken on the system using the root account.
3.1.1 3.1.5 | Prevent Login to Accounts With Empty Password | If an account is configured for password authentication but does not have an assigned password, it may be possible to log into the account without authentication. Remove any instances of the `nullok` in `/etc/pam.d/system-auth` to prevent logins with empty passwords. | If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
3.1.1 3.1.6 | Direct root Logins Not Allowed | To further limit access to the `root` account, administrators can disable root logins at the console by editing the `/etc/securetty` file. This file lists all devices the root user is allowed to login to. If the file does not exist at all, the root user can login through any communication device on the system, whether via the console or via a raw network interface. This is dangerous as user can login to the system as root via Telnet, which sends the password in plain text over the network. By default, Oracle Linux 7's `/etc/securetty` file only allows the root user to login at the console physically attached to the system. To prevent root from logging in, remove the contents of this file. To prevent direct root logins, remove the contents of this file by typing the following command:
    $ sudo echo > /etc/securetty
| Disabling direct root logins ensures proper accountability and multifactor authentication to privileged accounts. Users will first login, then escalate to privileged (root) access via su / sudo. This is required for FISMA Low and FISMA Moderate systems.
3.1.1 | Disable GDM Automatic Login | The GNOME Display Manager (GDM) can allow users to automatically login without user interaction or credentials. User should always be required to authenticate themselves to the system that they are authorized to use. To disable user ability to automatically login to the system, set the `AutomaticLoginEnable` to `false` in the `[daemon]` section in `/etc/gdm/custom.conf`. For example:
    [daemon]
    AutomaticLoginEnable=false
| Failure to restrict system access to authenticated users negatively impacts operating system security.
3.1.1 3.4.5 | Require Authentication for Emergency Systemd Target | Emergency mode is intended as a system recovery method, providing a single user root access to the system during a failed boot sequence. By default, Emergency mode is protected by requiring a password and is set in `/usr/lib/systemd/system/emergency.service`. | This prevents attackers with physical access from trivially bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password.
3.1.1 3.4.5 | Require Authentication for Single User Mode | Single-user mode is intended as a system recovery method, providing a single user root access to the system by providing a boot option at startup. By default, no authentication is performed if single-user mode is selected. By default, single-user mode is protected by requiring a password and is set in `/usr/lib/systemd/system/rescue.service`. | This prevents attackers with physical access from trivially bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password.
3.1.1 3.1.5 | Disable SSH Access via Empty Passwords | Disallow SSH login with empty passwords. The default SSH configuration disables logins with empty passwords. The appropriate configuration is used if no value is set for `PermitEmptyPasswords`. To explicitly disallow SSH login from accounts with empty passwords, add or correct the following line in `/etc/ssh/sshd_config`:
    PermitEmptyPasswords no
Any accounts with empty passwords should be disabled immediately, and PAM configuration should prevent users from being able to assign themselves empty passwords. | Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.
3.1.1 | Disable GDM Guest Login | The GNOME Display Manager (GDM) can allow users to login without credentials which can be useful for public kiosk scenarios. Allowing users to login without credentials or "guest" account access has inherent security risks and should be disabled. To do disable timed logins or guest account access, set the `TimedLoginEnable` to `false` in the `[daemon]` section in `/etc/gdm/custom.conf`. For example:
    [daemon]
    TimedLoginEnable=false
| Failure to restrict system access to authenticated users negatively impacts operating system security.
3.1.1 3.1.5 | Verify Only Root Has UID 0 | If any account other than root has a UID of 0, this misconfiguration should be investigated and the accounts other than root should be removed or have their UID changed. If the account is associated with system commands or applications the UID should be changed to one greater than "0" but less than "1000." Otherwise assign a UID greater than "1000" that has not already been assigned. | An account has root authority if it has a UID of 0. Multiple accounts with a UID of 0 afford more opportunity for potential intruders to guess a password for a privileged account. Proper configuration of sudo is recommended to afford multiple system administrators access to root privileges in an accountable manner.
3.1.1 3.1.5 | Disable SSH Root Login | The root user should never be allowed to login to a system directly over a network. To disable root login via SSH, add or correct the following line in `/etc/ssh/sshd_config`:
    PermitRootLogin no
| Even though the communications channel may be encrypted, an additional layer of security is gained by extending the policy of not logging directly on as root. In addition, logging in with a user-specific account provides individual accountability of actions performed on the system and also helps to minimize direct attack attempts on root's password.
3.1.1 3.1.5 | Restrict Serial Port Root Logins | To restrict root logins on serial ports, ensure lines of this form do not appear in `/etc/securetty`:
    ttyS0
    ttyS1
| Preventing direct root login to serial port interfaces helps ensure accountability for actions taken on the systems using the root account.
3.1.2 3.4.5 | Verify that Interactive Boot is Disabled | Oracle Linux 7 systems support an "interactive boot" option that can be used to prevent services from being started. On a Oracle Linux 7 system, interactive boot can be enabled by providing a `1`, `yes`, `true`, or `on` value to the `systemd.confirm_spawn` kernel argument in `/etc/default/grub`. Remove any instance of
    systemd.confirm_spawn=(1|yes|true|on)
from the kernel arguments in that file to disable interactive boot. It is also required to change the runtime configuration, run:
    /sbin/grubby --update-kernel=ALL --remove-args="systemd.confirm_spawn"
| Using interactive boot, the console user could disable auditing, firewalls, or other services, weakening system security.
3.1.2 3.7.2 | Ensure SELinux Not Disabled in the kernel arguments | SELinux can be disabled at boot time by disabling it via a kernel argument. Remove any instances of `selinux=0` from the kernel arguments in that file to prevent SELinux from being disabled at boot. | Disabling a major host protection feature, such as SELinux, at boot time prevents it from confining system services at boot time. Further, it increases the chances that it will remain off during system operation.
3.1.2 | Disable Ctrl-Alt-Del Reboot Key Sequence in GNOME3 | By default, `GNOME` will reboot the system if the `Ctrl-Alt-Del` key sequence is pressed. To configure the system to ignore the `Ctrl-Alt-Del` key sequence from the Graphical User Interface (GUI) instead of rebooting the system, add or set `logout` to `''` in `/etc/dconf/db/local.d/00-security-settings`. For example:
    [org/gnome/settings-daemon/plugins/media-keys]
    logout=''
Once the settings have been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/settings-daemon/plugins/media-keys/logout
After the settings have been set, run `dconf update`. | A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.
3.1.2 3.7.2 | Ensure SELinux State is Enforcing | The SELinux state should be set to ``enforcing`` at system boot time. In the file `/etc/selinux/config`, add or correct the following line to configure the system to boot into enforcing mode:
    SELINUX=enforcing
| Setting the SELinux state to enforcing ensures SELinux is able to confine potentially compromised processes to the security policy, which is designed to prevent them from causing damage to the system or further elevating their privileges.
3.1.2 3.7.2 | Configure SELinux Policy | The SELinux `targeted` policy is appropriate for general-purpose desktops and servers, as well as systems in many other roles. To configure the system to use this policy, add or correct the following line in `/etc/selinux/config`:
    SELINUXTYPE=targeted
Other policies, such as `mls`, provide additional security labeling and greater confinement but are not compatible with many general-purpose use cases. | Setting the SELinux policy to `targeted` or a more specialized policy ensures the system will confine processes that are likely to be targeted for exploitation, such as network or system services. Note: During the development or debugging of SELinux modules, it is common to temporarily place non-production systems in `permissive` mode. In such temporary cases, SELinux policies should be developed, and once work is completed, the system should be reconfigured to ``.
3.1.2 3.1.5 3.7.2 | Ensure No Daemons are Unconfined by SELinux | Daemons for which the SELinux policy does not contain rules will inherit the context of the parent process. Because daemons are launched during startup and descend from the `init` process, they inherit the `unconfined_service_t` context. To check for unconfined daemons, run the following command:
    $ sudo ps -eZ | grep "unconfined_service_t"
It should produce no output in a well-configured system. | Daemons which run with the `unconfined_service_t` context may cause AVC denials, or allow privileges that the daemon does not require.
3.1.2 | Disable the GNOME3 Login Restart and Shutdown Buttons | In the default graphical environment, users logging directly into the system are greeted with a login screen that allows any user, known or unknown, the ability the ability to shutdown or restart the system. This functionality should be disabled by setting `disable-restart-buttons` to `true`. To disable, add or edit `disable-restart-buttons` to `/etc/dconf/db/gdm.d/00-security-settings`. For example:
    [org/gnome/login-screen]
    disable-restart-buttons=true
Once the setting has been added, add a lock to `/etc/dconf/db/gdm.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/login-screen/disable-restart-buttons
After the settings have been set, run `dconf update`. | A user who is at the console can reboot the system at the login screen. If restart or shutdown buttons are pressed at the login screen, this can create the risk of short-term loss of availability of systems due to reboot.
3.1.2 3.1.5 3.7.2 | Ensure No Device Files are Unlabeled by SELinux | Device files, which are used for communication with important system resources, should be labeled with proper SELinux types. If any device files carry the SELinux type `device_t` or `unlabeled_t`, report the bug so that policy can be corrected. Supply information about what the device is and what programs use it. To check for incorrectly labeled device files, run following commands:
    $ sudo find /dev -context *:device_t:* \( -type c -o -type b \) -printf "%p %Z\n"
    $ sudo find /dev -context *:unlabeled_t:* \( -type c -o -type b \) -printf "%p %Z\n"
It should produce no output in a well-configured system. | If a device file carries the SELinux type `device_t` or `unlabeled_t`, then SELinux cannot properly restrict access to the device file.
3.1.2 3.7.2 | Ensure SELinux Not Disabled in /etc/default/grub | SELinux can be disabled at boot time by an argument in `/etc/default/grub`. Remove any instances of `selinux=0` from the kernel arguments in that file to prevent SELinux from being disabled at boot. | Disabling a major host protection feature, such as SELinux, at boot time prevents it from confining system services at boot time. Further, it increases the chances that it will remain off during system operation.
3.1.3 3.4.7 | Verify firewalld Enabled | The `firewalld` service can be enabled with the following command:
    $ sudo systemctl enable firewalld.service
| Access control methods provide the ability to enhance system security posture by restricting services and known good IP addresses and address ranges. This prevents connections from unknown hosts and protocols.
3.1.3 3.4.7 3.13.6 | Set Default firewalld Zone for Incoming Packets | To set the default zone to `drop` for the built-in default zone which processes incoming IPv4 and IPv6 packets, modify the following line in `/etc/firewalld/firewalld.conf` to be:
    DefaultZone=drop
| In `firewalld` the default zone is applied only after all the applicable rules in the table are examined for a match. Setting the default zone to `drop` implements proper design for a firewall, i.e. any packets which are not explicitly permitted should not be accepted.
3.1.5 | Disable User Administration in GNOME3 | By default, `GNOME` will allow all users to have some administratrion capability. This should be disabled so that non-administrative users are not making configuration changes. To configure the system to disable user administration capability in the Graphical User Interface (GUI), add or set `user-administration-disabled` to `true` in `/etc/dconf/db/local.d/00-security-settings`. For example:
    [org/gnome/desktop/lockdown]
    user-administration-disabled=true
Once the settings have been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/desktop/lockdown/user-administration-disabled
After the settings have been set, run `dconf update`. | Allowing all users to have some administratrive capabilities to the system through the Graphical User Interface (GUI) when they would not have them otherwise could allow unintended configuration changes as well as a nefarious user the capability to make system changes such as adding new accounts, etc.
3.1.5 | Restrict Access to Kernel Message Buffer | To set the runtime status of the `kernel.dmesg_restrict` kernel parameter, run the following command:
    $ sudo sysctl -w kernel.dmesg_restrict=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    kernel.dmesg_restrict = 1
| Unprivileged access to the kernel syslog can expose sensitive kernel address information.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - fsetxattr | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Ensure auditd Collects Information on Kernel Module Unloading - delete_module | To capture kernel module unloading events, use following line, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S delete_module -F key=modules
Place to add the line depends on a way `auditd` daemon is configured. If it is configured to use the `augenrules` program (the default), add the line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility, add the line to file `/etc/audit/audit.rules`. | The removal of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - lchown | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Record Unsuccessul Delete Attempts to Files - unlink | The audit system should collect unsuccessful file deletion attempts for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S unlink -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
    -a always,exit -F arch=b32 -S unlink -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S unlink -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
    -a always,exit -F arch=b64 -S unlink -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
| Unsuccessful attempts to delete files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Record Unsuccessful Creation Attempts to Files - open O_CREAT | The audit system should collect unauthorized file accesses for all users and root. The `open` syscall can be used to create new files when O_CREAT flag is specified. The following auidt rules will asure that unsuccessful attempts to create a file via `open` syscall are collected. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the rules below to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the rules below to `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S open -F a1&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b32 -S open -F a1&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open -F a1&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b64 -S open -F a1&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - gpasswd | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/gpasswd -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/gpasswd -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record attempts to alter time through settimeofday | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S settimeofday -F key=audit_time_rules
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S settimeofday -F key=audit_time_rules
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S settimeofday -F key=audit_time_rules
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S settimeofday -F key=audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
    -a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
| Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
3.1.7 | Install PAE Kernel on Supported 32-bit x86 Systems | Systems that are using the 64-bit x86 kernel package do not need to install the kernel-PAE package because the 64-bit x86 kernel already includes this support. However, if the system is 32-bit and also supports the PAE and NX features as determined in the previous section, the kernel-PAE package should be installed to enable XD or NX support. The `kernel-PAE` package can be installed with the following command:
    $ sudo yum install kernel-PAE
The installation process should also have configured the bootloader to load the new kernel at boot. Verify this after reboot and modify `/etc/default/grub` if necessary. | On 32-bit systems that support the XD or NX bit, the vendor-supplied PAE kernel is required to enable either Execute Disable (XD) or No Execute (NX) support.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - umount | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/umount -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/umount -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Ensure auditd Collects File Deletion Events by User - unlink | At a minimum, the audit system should collect file deletion events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S unlink -F auid>=1000 -F auid!=unset -F key=delete
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S unlink -F auid>=1000 -F auid!=unset -F key=delete
| Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
3.1.7 | Ensure auditd Rules For Unauthorized Attempts To open Are Ordered Correctly | The audit system should collect detailed unauthorized file accesses for all users and root. To correctly identify unsuccessful creation, unsuccessful modification and unsuccessful access of files via `open` syscall the audit rules collecting these events need to be in certain order. The more specific rules need to come before the less specific rules. The reason for that is that more specific rules cover a subset of events covered in the less specific rules, thus, they need to come before to not be overshadowed by less specific rules, which match a bigger set of events. Make sure that rules for unsuccessful calls of `open` syscall are in the order shown below. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), check the order of rules below in a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, check the order of rules below in `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S open -F a1&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b32 -S open -F a1&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b32 -S open -F a1&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b32 -S open -F a1&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
    -a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open -F a1&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b64 -S open -F a1&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b64 -S open -F a1&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b64 -S open -F a1&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
    -a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
| The more specific rules cover a subset of events covered by the less specific rules. By ordering them from more specific to less specific, it is assured that the less specific rule will not catch events better recorded by the more specific rule.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - lsetxattr | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - removexattr | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Record Unsuccessful Access Attempts to Files - creat | At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Record Unsuccessful Access Attempts to Files - ftruncate | At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S ftruncate -F exiu=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands | The audit system should collect information about usage of privileged commands for all users and root. To find the relevant setuid / setgid programs, run the following command for each local partition PART:
    $ sudo find PART -xdev -type f -perm -4000 -o -type f -perm -2000 2>/dev/null
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d` for each setuid / setgid program on the system, replacing the SETUID_PROG_PATH part with the full path of that setuid / setgid program in the list:
    -a always,exit -F path=SETUID_PROG_PATH -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules` for each setuid / setgid program on the system, replacing the SETUID_PROG_PATH part with the full path of that setuid / setgid program in the list:
    -a always,exit -F path=SETUID_PROG_PATH -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - su | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/su -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/su -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Disable GNOME3 Automount running | The system's default desktop environment, GNOME3, will mount devices and removable media (such as DVDs, CDs and USB flash drives) whenever they are inserted into the system. To disable autorun-never within GNOME3, add or set `autorun-never` to `true` in `/etc/dconf/db/local.d/00-security-settings`. For example:
    [org/gnome/desktop/media-handling]
    autorun-never=true
Once the settings have been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/desktop/media-handling/autorun-never
After the settings have been set, run `dconf update`. | Disabling automatic mount running in GNOME3 can prevent the introduction of malware via removable media. It will, however, also prevent desktop users from legitimate use of removable media.
3.1.7 | Record Unsuccessul Delete Attempts to Files - unlinkat | The audit system should collect unsuccessful file deletion attempts for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S unlinkat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
    -a always,exit -F arch=b32 -S unlinkat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S unlinkat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
    -a always,exit -F arch=b64 -S unlinkat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
| Unsuccessful attempts to delete files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - postdrop | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/sbin/postdrop -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/sbin/postdrop -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record attempts to alter time through adjtimex | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S adjtimex -F key=audit_time_rules
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S adjtimex -F key=audit_time_rules
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S adjtimex -F key=audit_time_rules
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S adjtimex -F key=audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
    -a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
| Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
3.1.7 | Record Unsuccessful Access Attempts to Files - open_by_handle_at | At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Record Attempts to Alter Time Through clock_settime | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S clock_settime -F a0=0x0 -F key=time-change
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S clock_settime -F a0=0x0 -F key=time-change
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
    -a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
| Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
3.1.7 | Record Unsuccessful Access Attempts to Files - truncate | At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Record Unsuccessful Creation Attempts to Files - openat O_CREAT | The audit system should collect unauthorized file accesses for all users and root. The `openat` syscall can be used to create new files when O_CREAT flag is specified. The following auidt rules will asure that unsuccessful attempts to create a file via `openat` syscall are collected. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the rules below to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the rules below to `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S openat -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b32 -S openat -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S openat -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b64 -S openat -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - sudo | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/sudo -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/sudo -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - pt_chown | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/libexec/pt_chown -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/libexec/pt_chown -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Ensure auditd Collects Information on Kernel Module Loading and Unloading | To capture kernel module loading and unloading events, use following lines, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S init_module,finit_module,delete_module -F key=modules
The place to add the lines depends on a way `auditd` daemon is configured. If it is configured to use the `augenrules` program (the default), add the lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility, add the lines to file `/etc/audit/audit.rules`. | The addition/removal of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
3.1.7 | Record Unsuccessful Access Attempts to Files - openat | At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Record Any Attempts to Run chcon | At a minimum, the audit system should collect any execution attempt of the `chcon` command for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/chcon -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F path=/usr/bin/chcon -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record Unsuccessful Modification Attempts to Files - open_by_handle_at O_TRUNC_WRITE | The audit system should collect detailed unauthorized file accesses for all users and root. The `open_by_handle_at` syscall can be used to modify files if called for write operation of with O_TRUNC_WRITE flag. The following auidt rules will asure that unsuccessful attempts to modify a file via `open_by_handle_at` syscall are collected. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the rules below to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the rules below to `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S open_by_handle_at -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b32 -S open_by_handle_at -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open_by_handle_at -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b64 -S open_by_handle_at -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Ensure auditd Collects File Deletion Events by User | At a minimum the audit system should collect file deletion events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S rmdir,unlink,unlinkat,rename,renameat -F auid>=1000 -F auid!=unset -F key=delete
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S rmdir,unlink,unlinkat,rename -S renameat -F auid>=1000 -F auid!=unset -F key=delete
| Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
3.1.7 | Record Attempts to Alter Logon and Logout Events - lastlog | The audit system already collects login information for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d` in order to watch for attempted manual edits of files involved in storing logon events:
    -w /var/log/lastlog -p wa -k logins
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file in order to watch for unattempted manual edits of files involved in storing logon events:
    -w /var/log/lastlog -p wa -k logins
| Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - setxattr | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - fremovexattr | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Record Events that Modify User/Group Information | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, in order to capture events that modify account changes:
    -w /etc/group -p wa -k audit_rules_usergroup_modification
    -w /etc/passwd -p wa -k audit_rules_usergroup_modification
    -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
    -w /etc/shadow -p wa -k audit_rules_usergroup_modification
    -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file, in order to capture events that modify account changes:
    -w /etc/group -p wa -k audit_rules_usergroup_modification
    -w /etc/passwd -p wa -k audit_rules_usergroup_modification
    -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
    -w /etc/shadow -p wa -k audit_rules_usergroup_modification
    -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
| In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - fchown | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - chown | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Ensure auditd Collects System Administrator Actions | At a minimum, the audit system should collect administrator actions for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/sudoers -p wa -k actions
    -w /etc/sudoers.d/ -p wa -k actions
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -w /etc/sudoers -p wa -k actions
    -w /etc/sudoers.d/ -p wa -k actions
| The actions taken by system administrators should be audited to keep a record of what was executed on the system, as well as, for accountability purposes.
3.1.7 | Disable GNOME3 Automount Opening | The system's default desktop environment, GNOME3, will mount devices and removable media (such as DVDs, CDs and USB flash drives) whenever they are inserted into the system. To disable automount-open within GNOME3, add or set `automount-open` to `false` in `/etc/dconf/db/local.d/00-security-settings`. For example:
    [org/gnome/desktop/media-handling]
    automount-open=false
Once the settings have been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/desktop/media-handling/automount-open
After the settings have been set, run `dconf update`. | Disabling automatic mounting in GNOME3 can prevent the introduction of malware via removable media. It will, however, also prevent desktop users from legitimate use of removable media.
3.1.7 | Ensure auditd Collects Unauthorized Access Attempts to Files (unsuccessful) | At a minimum the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Record Events that Modify the System's Network Environment | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S sethostname,setdomainname -F key=audit_rules_networkconfig_modification
    -w /etc/issue -p wa -k audit_rules_networkconfig_modification
    -w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
    -w /etc/hosts -p wa -k audit_rules_networkconfig_modification
    -w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S sethostname,setdomainname -F key=audit_rules_networkconfig_modification
    -w /etc/issue -p wa -k audit_rules_networkconfig_modification
    -w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
    -w /etc/hosts -p wa -k audit_rules_networkconfig_modification
    -w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
| The network environment should not be modified by anything other than administrator action. Any change to network parameters should be audited.
3.1.7 | Record Attempts to Alter Process and Session Initiation Information | The audit system already collects process information for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d` in order to watch for attempted manual edits of files involved in storing such process information:
    -w /var/run/utmp -p wa -k session
    -w /var/log/btmp -p wa -k session
    -w /var/log/wtmp -p wa -k session
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file in order to watch for attempted manual edits of files involved in storing such process information:
    -w /var/run/utmp -p wa -k session
    -w /var/log/btmp -p wa -k session
    -w /var/log/wtmp -p wa -k session
| Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - passwd | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/passwd -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/passwd -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record Any Attempts to Run restorecon | At a minimum, the audit system should collect any execution attempt of the `restorecon` command for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/sbin/restorecon -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F path=/usr/sbin/restorecon -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record Any Attempts to Run semanage | At a minimum, the audit system should collect any execution attempt of the `semanage` command for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/sbin/semanage -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F path=/usr/sbin/semanage -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record Attempts to Alter Time Through stime | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d` for both 32 bit and 64 bit systems:
    -a always,exit -F arch=b32 -S stime -F key=audit_time_rules
Since the 64 bit version of the "stime" system call is not defined in the audit lookup table, the corresponding "-F arch=b64" form of this rule is not expected to be defined on 64 bit systems (the aforementioned "-F arch=b32" stime rule form itself is sufficient for both 32 bit and 64 bit systems). If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file for both 32 bit and 64 bit systems:
    -a always,exit -F arch=b32 -S stime -F key=audit_time_rules
Since the 64 bit version of the "stime" system call is not defined in the audit lookup table, the corresponding "-F arch=b64" form of this rule is not expected to be defined on 64 bit systems (the aforementioned "-F arch=b32" stime rule form itself is sufficient for both 32 bit and 64 bit systems). The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined system calls:
    -a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
| Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - userhelper | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/sbin/userhelper -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/sbin/userhelper -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Ensure auditd Collects Information on Kernel Module Loading - init_module | To capture kernel module loading events, use following line, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S init_module -F key=modules
Place to add the line depends on a way `auditd` daemon is configured. If it is configured to use the `augenrules` program (the default), add the line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility, add the line to file `/etc/audit/audit.rules`. | The addition of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
3.1.7 | Enable NX or XD Support in the BIOS | Reboot the system and enter the BIOS or Setup configuration menu. Navigate the BIOS configuration menu and make sure that the option is enabled. The setting may be located under a Security section. Look for Execute Disable (XD) on Intel-based systems and No Execute (NX) on AMD-based systems. | Computers with the ability to prevent this type of code execution frequently put an option in the BIOS that will allow users to turn the feature on or off at will.
3.1.7 | Ensure auditd Collects File Deletion Events by User - rmdir | At a minimum, the audit system should collect file deletion events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S rmdir -F auid>=1000 -F auid!=unset -F key=delete
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S rmdir -F auid>=1000 -F auid!=unset -F key=delete
| Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - crontab | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/crontab -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/crontab -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Ensure auditd Collects File Deletion Events by User - unlinkat | At a minimum, the audit system should collect file deletion events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete
| Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
3.1.7 | Disable GNOME3 Automounting | The system's default desktop environment, GNOME3, will mount devices and removable media (such as DVDs, CDs and USB flash drives) whenever they are inserted into the system. To disable automount within GNOME3, add or set `automount` to `false` in `/etc/dconf/db/local.d/00-security-settings`. For example:
    [org/gnome/desktop/media-handling]
    automount=false
Once the settings have been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/desktop/media-handling/automount
After the settings have been set, run `dconf update`. | Disabling automatic mounting in GNOME3 can prevent the introduction of malware via removable media. It will, however, also prevent desktop users from legitimate use of removable media.
3.1.7 | Record Unsuccessful Modification Attempts to Files - openat O_TRUNC_WRITE | The audit system should collect detailed unauthorized file accesses for all users and root. The `openat` syscall can be used to modify files if called for write operation of with O_TRUNC_WRITE flag. The following auidt rules will asure that unsuccessful attempts to modify a file via `openat` syscall are collected. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the rules below to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the rules below to `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S openat -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b32 -S openat -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S openat -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b64 -S openat -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Record Unsuccessul Delete Attempts to Files - rename | The audit system should collect unsuccessful file deletion attempts for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S rename -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
    -a always,exit -F arch=b32 -S rename -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S rename -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
    -a always,exit -F arch=b64 -S rename -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
| Unsuccessful attempts to delete files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Record Attempts to Alter the localtime File | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/localtime -p wa -k audit_time_rules
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -w /etc/localtime -p wa -k audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport and should always be used. | Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
3.1.7 | Record Any Attempts to Run setsebool | At a minimum, the audit system should collect any execution attempt of the `setsebool` command for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/sbin/setsebool -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F path=/usr/sbin/setsebool -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record Unsuccessful Modification Attempts to Files - open O_TRUNC_WRITE | The audit system should collect detailed unauthorized file accesses for all users and root. The `open` syscall can be used to modify files if called for write operation of with O_TRUNC_WRITE flag. The following auidt rules will asure that unsuccessful attempts to modify a file via `open` syscall are collected. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the rules below to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the rules below to `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S open -F a1&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b32 -S open -F a1&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open -F a1&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b64 -S open -F a1&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - postqueue | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/sbin/postqueue -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/sbin/postqueue -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Ensure auditd Unauthorized Access Attempts To open_by_handle_at Are Ordered Correctly | The audit system should collect detailed unauthorized file accesses for all users and root. To correctly identify unsuccessful creation, unsuccessful modification and unsuccessful access of files via `open_by_handle_at` syscall the audit rules collecting these events need to be in certain order. The more specific rules need to come before the less specific rules. The reason for that is that more specific rules cover a subset of events covered in the less specific rules, thus, they need to come before to not be overshadowed by less specific rules, which match a bigger set of events. Make sure that rules for unsuccessful calls of `open_by_handle_at` syscall are in the order shown below. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), check the order of rules below in a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, check the order of rules below in `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S open_by_handle_at -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b32 -S open_by_handle_at -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b32 -S open_by_handle_at -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b32 -S open_by_handle_at -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b32 -S open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
    -a always,exit -F arch=b32 -S open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open_by_handle_at -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b64 -S open_by_handle_at -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b64 -S open_by_handle_at -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b64 -S open_by_handle_at -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b64 -S open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
    -a always,exit -F arch=b64 -S open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
| The more specific rules cover a subset of events covered by the less specific rules. By ordering them from more specific to less specific, it is assured that the less specific rule will not catch events better recorded by the more specific rule.
3.1.7 | Enable Randomized Layout of Virtual Address Space | To set the runtime status of the `kernel.randomize_va_space` kernel parameter, run the following command:
    $ sudo sysctl -w kernel.randomize_va_space=2
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    kernel.randomize_va_space = 2
| Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code they have introduced into a process's address space during an attempt at exploitation. Additionally, ASLR makes it more difficult for an attacker to know the location of existing code in order to re-purpose it using return oriented programming (ROP) techniques.
3.1.7 | Record Unsuccessul Delete Attempts to Files - renameat | The audit system should collect unsuccessful file deletion attempts for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S renameat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
    -a always,exit -F arch=b32 -S renameat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S renameat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
    -a always,exit -F arch=b64 -S renameat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
| Unsuccessful attempts to delete files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - fchmod | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - chmod | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - fchmodat | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - ssh-keysign | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/libexec/openssh/ssh-keysign -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/libexec/openssh/ssh-keysign -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record Events that Modify User/Group Information - /etc/group | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, in order to capture events that modify account changes:
    -w /etc/group -p wa -k audit_rules_usergroup_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file, in order to capture events that modify account changes:
    -w /etc/group -p wa -k audit_rules_usergroup_modification
| In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
3.1.7 | Record Attempts to Alter Logon and Logout Events - faillock | The audit system already collects login information for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d` in order to watch for attempted manual edits of files involved in storing logon events:
    -w /var/run/faillock -p wa -k logins
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file in order to watch for unattempted manual edits of files involved in storing logon events:
    -w /var/run/faillock -p wa -k logins
| Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion.
3.1.7 | Record Events that Modify User/Group Information - /etc/security/opasswd | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, in order to capture events that modify account changes:
    -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file, in order to capture events that modify account changes:
    -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
| In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - newgrp | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/newgrp -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/newgrp -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record Events that Modify User/Group Information - /etc/shadow | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, in order to capture events that modify account changes:
    -w /etc/shadow -p wa -k audit_rules_usergroup_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file, in order to capture events that modify account changes:
    -w /etc/shadow -p wa -k audit_rules_usergroup_modification
| In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
3.1.7 | Ensure auditd Collects File Deletion Events by User - rename | At a minimum, the audit system should collect file deletion events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S rename -F auid>=1000 -F auid!=unset -F key=delete
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S rename -F auid>=1000 -F auid!=unset -F key=delete
| Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
3.1.7 | Ensure auditd Collects File Deletion Events by User - renameat | At a minimum, the audit system should collect file deletion events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S renameat -F auid>=1000 -F auid!=unset -F key=delete
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S renameat -F auid>=1000 -F auid!=unset -F key=delete
| Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - lremovexattr | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - chsh | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/chsh -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/chsh -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Ensure auditd Collects Information on Kernel Module Loading and Unloading - finit_module | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d` to capture kernel module loading and unloading events, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S finit_module -F key=modules
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file in order to capture kernel module loading and unloading events, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S finit_module -F key=modules
| The addition/removal of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - chage | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/chage -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/chage -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record Unsuccessful Creation Attempts to Files - open_by_handle_at O_CREAT | The audit system should collect unauthorized file accesses for all users and root. The `open_by_handle_at` syscall can be used to create new files when O_CREAT flag is specified. The following auidt rules will asure that unsuccessful attempts to create a file via `open_by_handle_at` syscall are collected. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the rules below to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the rules below to `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S open_by_handle_at -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b32 -S open_by_handle_at -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open_by_handle_at -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b64 -S open_by_handle_at -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Ensure auditd Collects Information on Exporting to Media (successful) | At a minimum, the audit system should collect media exportation events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S mount -F auid>=1000 -F auid!=unset -F key=export
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 or b64 as appropriate for your system:
    -a always,exit -F arch=ARCH -S mount -F auid>=1000 -F auid!=unset -F key=export
| The unauthorized exportation of data to external media could result in an information leak where classified information, Privacy Act information, and intellectual property could be lost. An audit trail should be created each time a filesystem is mounted to help identify and guard against information loss.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - pam_timestamp_check | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/sbin/pam_timestamp_check
    -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/sbin/pam_timestamp_check
    -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record Events that Modify the System's Discretionary Access Controls - fchownat | At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
| The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
3.1.7 | Record Attempts to Alter Logon and Logout Events | The audit system already collects login information for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d` in order to watch for attempted manual edits of files involved in storing logon events:
    -w /var/log/tallylog -p wa -k logins
    -w /var/run/faillock -p wa -k logins
    -w /var/log/lastlog -p wa -k logins
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file in order to watch for unattempted manual edits of files involved in storing logon events:
    -w /var/log/tallylog -p wa -k logins
    -w /var/run/faillock -p wa -k logins
    -w /var/log/lastlog -p wa -k logins
| Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion.
3.1.7 | Record Unsuccessful Access Attempts to Files - open | At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
| Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - unix_chkpwd | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/sbin/unix_chkpwd -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/sbin/unix_chkpwd -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Ensure auditd Rules For Unauthorized Attempts To openat Are Ordered Correctly | The audit system should collect detailed unauthorized file accesses for all users and root. To correctly identify unsuccessful creation, unsuccessful modification and unsuccessful access of files via `openat` syscall the audit rules collecting these events need to be in certain order. The more specific rules need to come before the less specific rules. The reason for that is that more specific rules cover a subset of events covered in the less specific rules, thus, they need to come before to not be overshadowed by less specific rules, which match a bigger set of events. Make sure that rules for unsuccessful calls of `openat` syscall are in the order shown below. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), check the order of rules below in a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, check the order of rules below in `/etc/audit/audit.rules` file.
    -a always,exit -F arch=b32 -S openat -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b32 -S openat -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b32 -S openat -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b32 -S openat -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b32 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
    -a always,exit -F arch=b32 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S openat -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b64 -S openat -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-create
    -a always,exit -F arch=b64 -S openat -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b64 -S openat -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-modification
    -a always,exit -F arch=b64 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
    -a always,exit -F arch=b64 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccesful-access
| The more specific rules cover a subset of events covered by the less specific rules. By ordering them from more specific to less specific, it is assured that the less specific rule will not catch events better recorded by the more specific rule.
3.1.7 | Record Attempts to Alter Logon and Logout Events - tallylog | The audit system already collects login information for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d` in order to watch for attempted manual edits of files involved in storing logon events:
    -w /var/log/tallylog -p wa -k logins
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file in order to watch for unattempted manual edits of files involved in storing logon events:
    -w /var/log/tallylog -p wa -k logins
| Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion.
3.1.7 | Record Events that Modify User/Group Information - /etc/gshadow | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, in order to capture events that modify account changes:
    -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file, in order to capture events that modify account changes:
    -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
| In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
3.1.7 | Ensure auditd Collects Information on the Use of Privileged Commands - sudoedit | At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/sudoedit -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/sudoedit -F auid>=1000 -F auid!=unset -F key=privileged
| Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
3.1.7 | Record Events that Modify User/Group Information - /etc/passwd | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, in order to capture events that modify account changes:
    -w /etc/passwd -p wa -k audit_rules_usergroup_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file, in order to capture events that modify account changes:
    -w /etc/passwd -p wa -k audit_rules_usergroup_modification
| In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
3.1.8 | Set the GNOME3 Login Number of Failures | In the default graphical environment, the GNOME3 login screen and be configured to restart the authentication process after a configured number of attempts. This can be configured by setting `allowed-failures` to `3` or less. To enable, add or edit `allowed-failures` to `/etc/dconf/db/gdm.d/00-security-settings`. For example:
    [org/gnome/login-screen]
    allowed-failures=3
Once the setting has been added, add a lock to `/etc/dconf/db/gdm.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/login-screen/allowed-failures
After the settings have been set, run `dconf update`. | Setting the password retry prompts that are permitted on a per-session basis to a low value requires some software, such as SSH, to re-connect. This can slow down and draw additional attention to some types of password-guessing attacks.
3.1.8 | Lock Accounts After Failed Password Attempts | This rule configures the system to lock out accounts after a number of incorrect login attempts using `pam_faillock.so`. pam_faillock.so module requires multiple entries in pam files. These entries must be carefully defined to work as expected. In order to avoid any errors when manually editing these files, it is recommended to use the appropriate tools, such as `authselect` or `authconfig`, depending on the OS version. | Locking out user accounts after a number of incorrect attempts prevents direct password guessing attacks. In combination with the `silent` option, user enumeration attacks are also mitigated.
3.1.8 | Set Lockout Time for Failed Password Attempts | This rule configures the system to lock out accounts during a specified time period after a number of incorrect login attempts using `pam_faillock.so`. pam_faillock.so module requires multiple entries in pam files. These entries must be carefully defined to work as expected. In order to avoid any errors when manually editing these files, it is recommended to use the appropriate tools, such as `authselect` or `authconfig`, depending on the OS version. | Locking out user accounts after a number of incorrect attempts prevents direct password guessing attacks. Ensuring that an administrator is involved in unlocking locked accounts draws appropriate attention to such situations.
3.1.8 | Record Events that Modify the System's Mandatory Access Controls | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/selinux/ -p wa -k MAC-policy
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -w /etc/selinux/ -p wa -k MAC-policy
| The system's mandatory access policy (SELinux) should not be arbitrarily changed by anything other than administrator action. All changes to MAC policy should be audited.
3.1.9 | Set the GNOME3 Login Warning Banner Text | In the default graphical environment, configuring the login warning banner text in the GNOME Display Manager's login screen can be configured on the login screen by setting `banner-message-text` to `'APPROVED_BANNER'` where APPROVED_BANNER is the approved banner for your environment. To enable, add or edit `banner-message-text` to `/etc/dconf/db/gdm.d/00-security-settings`. For example:
    [org/gnome/login-screen]
    banner-message-text='APPROVED_BANNER'
Once the setting has been added, add a lock to `/etc/dconf/db/gdm.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/login-screen/banner-message-text
After the settings have been set, run `dconf update`. When entering a warning banner that spans several lines, remember to begin and end the string with `'` and use `\n` for new lines. | An appropriate warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers.
3.1.9 | Enable GNOME3 Login Warning Banner | In the default graphical environment, displaying a login warning banner in the GNOME Display Manager's login screen can be enabled on the login screen by setting `banner-message-enable` to `true`. To enable, add or edit `banner-message-enable` to `/etc/dconf/db/gdm.d/00-security-settings`. For example:
    [org/gnome/login-screen]
    banner-message-enable=true
Once the setting has been added, add a lock to `/etc/dconf/db/gdm.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/login-screen/banner-message-enable
After the settings have been set, run `dconf update`. The banner text must also be set. | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. For U.S. Government systems, system use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.
3.1.9 | Enable SSH Warning Banner | To enable the warning banner and ensure it is consistent across the system, add or correct the following line in `/etc/ssh/sshd_config`:
    Banner /etc/issue
Another section contains information on how to create an appropriate system-wide warning banner. | The warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers. Alternatively, systems whose ownership should not be obvious should ensure usage of a banner that does not provide easy attribution.
3.1.9 | Modify the System Login Banner | To configure the system login banner edit `/etc/issue`. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either: `You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.` OR: `I've read & consent to terms in IS user agreem't.` | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.
3.1.9 | Enable SSH Warning Banner | To enable the warning banner and ensure it is consistent across the system, add or correct the following line in `/etc/ssh/sshd_config`:
    Banner /etc/issue.net
Another section contains information on how to create an appropriate system-wide warning banner. | The warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers. Alternatively, systems whose ownership should not be obvious should ensure usage of a banner that does not provide easy attribution.
3.1.10 | Set GNOME3 Screensaver Lock Delay After Activation Period | To activate the locking delay of the screensaver in the GNOME3 desktop when the screensaver is activated, add or set `lock-delay` to `uint32 `0`` in `/etc/dconf/db/local.d/00-security-settings`. For example:
    [org/gnome/desktop/screensaver]
    lock-delay=uint32 0
Once the setting has been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/desktop/screensaver/lock-delay
After the settings have been set, run `dconf update`. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to logout because of the temporary nature of the absense.
3.1.10 | Enable GNOME3 Screensaver Idle Activation | To activate the screensaver in the GNOME3 desktop after a period of inactivity, add or set `idle-activation-enabled` to `true` in `/etc/dconf/db/local.d/00-security-settings`. For example:
    [org/gnome/desktop/screensaver]
    idle-activation-enabled=true
Once the setting has been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/desktop/screensaver/idle-activation-enabled
After the settings have been set, run `dconf update`. | A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, GNOME desktops can be configured to identify when a user's session has idled and take action to initiate the session lock. Enabling idle activation of the screensaver ensures the screensaver will be activated after the idle delay. Applications requiring continuous, real-time screen display (such as network management products) require the login session does not have administrator rights and the display station is located in a controlled-access area.
3.1.10 | Implement Blank Screensaver | To set the screensaver mode in the GNOME3 desktop to a blank screen, add or set `picture-uri` to `string ''` in `/etc/dconf/db/local.d/00-security-settings`. For example:
    [org/gnome/desktop/screensaver]
    picture-uri=''
Once the settings have been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/desktop/screensaver/picture-uri
After the settings have been set, run `dconf update`. | Setting the screensaver mode to blank-only conceals the contents of the display from passersby.
3.1.10 | Ensure Users Cannot Change GNOME3 Screensaver Lock After Idle Period | If not already configured, ensure that users cannot change GNOME3 screensaver lock settings by adding
    /org/gnome/desktop/screensaver/lock-enabled
to `/etc/dconf/db/local.d/00-security-settings`. For example:
    /org/gnome/desktop/screensaver/lock-enabled
After the settings have been set, run `dconf update`. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to logout because of the temporary nature of the absense.
3.1.10 | Install the screen Package | To enable console screen locking, install the `screen` package. The `screen` package can be installed with the following command:
    $ sudo yum install screen
Instruct users to begin new terminal sessions with the following command:
    $ screen
The console can now be locked with the following key combination:
    ctrl+a x
| A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operation system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The `screen` package allows for a session lock to be implemented and configured.
3.1.10 | Enable GNOME3 Screensaver Lock After Idle Period | To activate locking of the screensaver in the GNOME3 desktop when it is activated, add or set `lock-enabled` to `true` in `/etc/dconf/db/local.d/00-security-settings`. For example:
    [org/gnome/desktop/screensaver]
    lock-enabled=true
Once the settings have been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/desktop/screensaver/lock-enabled
After the settings have been set, run `dconf update`. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to logout because of the temporary nature of the absense.
3.1.10 | Ensure Users Cannot Change GNOME3 Screensaver Settings | If not already configured, ensure that users cannot change GNOME3 screensaver lock settings by adding `/org/gnome/desktop/screensaver/lock-delay` to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/desktop/screensaver/lock-delay
After the settings have been set, run `dconf update`. | A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, GNOME desktops can be configured to identify when a user's session has idled and take action to initiate the session lock. As such, users should not be allowed to change session settings.
3.1.10 | Set GNOME3 Screensaver Inactivity Timeout | The idle time-out value for inactivity in the GNOME3 desktop is configured via the `idle-delay` setting must be set under an appropriate configuration file(s) in the `/etc/dconf/db/local.d` directory and locked in `/etc/dconf/db/local.d/locks` directory to prevent user modification. For example, to configure the system for a 15 minute delay, add the following to `/etc/dconf/db/local.d/00-security-settings`:
    [org/gnome/desktop/session]
    idle-delay=uint32 900
Once the setting has been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/desktop/session/idle-delay
After the settings have been set, run `dconf update`. | A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, GNOME3 can be configured to identify when a user's session has idled and take action to initiate a session lock.
3.1.10 | Ensure Users Cannot Change GNOME3 Screensaver Idle Activation | If not already configured, ensure that users cannot change GNOME3 screensaver lock settings by adding
    /org/gnome/desktop/screensaver/idle-activation-enabled
to `/etc/dconf/db/local.d/00-security-settings`. For example:
    /org/gnome/desktop/screensaver/idle-activation-enabled
After the settings have been set, run `dconf update`. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to logout because of the temporary nature of the absense.
3.1.10 | Ensure Users Cannot Change GNOME3 Session Idle Settings | If not already configured, ensure that users cannot change GNOME3 session idle settings by adding `/org/gnome/desktop/session/idle-delay` to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/desktop/session/idle-delay
After the settings have been set, run `dconf update`. | A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, GNOME desktops can be configured to identify when a user's session has idled and take action to initiate the session lock. As such, users should not be allowed to change session settings.
3.1.11 | Set Interactive Session Timeout | Setting the `TMOUT` option in `/etc/profile` ensures that all user sessions will terminate based on inactivity. The `TMOUT` setting in a file loaded by `/etc/profile`, e.g. `/etc/profile.d/tmout.sh` should read as follows:
    TMOUT=600
| Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended.
3.1.11 | Set SSH Idle Timeout Interval | SSH allows administrators to set an idle timeout interval. After this interval has passed, the idle user will be automatically logged out. To set an idle timeout interval, edit the following line in `/etc/ssh/sshd_config` as follows:
    ClientAliveInterval 300
The timeout interval is given in seconds. For example, have a timeout of 10 minutes, set interval to 600. If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made in `/etc/ssh/sshd_config`. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle. | Terminating an idle ssh session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been let unattended.
3.1.11 | Set SSH Client Alive Count Max | The SSH server sends at most `ClientAliveCountMax` messages during a SSH session and waits for a response from the SSH client. The option `ClientAliveInterval` configures timeout after each `ClientAliveCountMax` message. If the SSH server does not receive a response from the client, then the connection is considered idle and terminated. For SSH earlier than v8.2, a `ClientAliveCountMax` value of `0` causes an idle timeout precisely when the `ClientAliveInterval` is set. Starting with v8.2, a value of `0` disables the timeout functionality completely. If the option is set to a number greater than `0`, then the idle session will be disconnected after `ClientAliveInterval * ClientAliveCountMax` seconds. | This ensures a user login will be terminated as soon as the `ClientAliveInterval` is reached.
3.1.11 | Set SSH Client Alive Count Max to zero | The SSH server sends at most `ClientAliveCountMax` messages during a SSH session and waits for a response from the SSH client. The option `ClientAliveInterval` configures timeout after each `ClientAliveCountMax` message. If the SSH server does not receive a response from the client, then the connection is considered idle and terminated. To ensure the SSH idle timeout occurs precisely when the `ClientAliveInterval` is set, set the `ClientAliveCountMax` to value of `0` in `/etc/ssh/sshd_config`: | This ensures a user login will be terminated as soon as the `ClientAliveInterval` is reached.
3.1.12 | Disable Host-Based Authentication | SSH's cryptographic host-based authentication is more secure than `.rhosts` authentication. However, it is not recommended that hosts unilaterally trust one another, even within an organization. The default SSH configuration disables host-based authentication. The appropriate configuration is used if no value is set for `HostbasedAuthentication`. To explicitly disable host-based authentication, add or correct the following line in `/etc/ssh/sshd_config`:
    HostbasedAuthentication no
| SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.
3.1.12 | Enable SSH Server firewalld Firewall Exception | By default, inbound connections to SSH's port are allowed. If the SSH server is being used but denied by the firewall, this exception should be added to the firewall configuration. To configure `firewalld` to allow access, run the following command(s): `firewall-cmd --permanent --add-service=ssh` | If inbound SSH connections are expected, adding a firewall rule exception will allow remote access through the SSH port.
3.1.12 | Enable Use of Strict Mode Checking | SSHs `StrictModes` option checks file and ownership permissions in the user's home directory `.ssh` folder before accepting login. If world- writable permissions are found, logon is rejected. The default SSH configuration has `StrictModes` enabled. The appropriate configuration is used if no value is set for `StrictModes`. To explicitly enable `StrictModes` in SSH, add or correct the following line in `/etc/ssh/sshd_config`:
    StrictModes yes
| If other users have access to modify user-specific SSH configuration files, they may be able to log into the system as another user.
3.1.12 | Require Credential Prompting for Remote Access in GNOME3 | By default, `GNOME` does not require credentials when using `Vino` for remote access. To configure the system to require remote credentials, add or set `authentication-methods` to `['vnc']` in `/etc/dconf/db/local.d/00-security-settings`. For example:
    [org/gnome/Vino]
    authentication-methods=['vnc']
Once the settings have been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/Vino/authentication-methods
After the settings have been set, run `dconf update`. | Username and password prompting is required for remote access. Otherwise, non-authorized and nefarious users can access the system freely.
3.1.12 | Disable SSH Support for .rhosts Files | SSH can emulate the behavior of the obsolete rsh command in allowing users to enable insecure access to their accounts via `.rhosts` files. The default SSH configuration disables support for `.rhosts`. The appropriate configuration is used if no value is set for `IgnoreRhosts`. To explicitly disable support for .rhosts files, add or correct the following line in `/etc/ssh/sshd_config`:
    IgnoreRhosts yes
| SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.
3.1.12 | Enable Use of Privilege Separation | When enabled, SSH will create an unprivileged child process that has the privilege of the authenticated user. To enable privilege separation in SSH, add or correct the following line in the `/etc/ssh/sshd_config` file:
    UsePrivilegeSeparation sandbox
| SSH daemon privilege separation causes the SSH process to drop root privileges when not needed which would decrease the impact of software vulnerabilities in the unprivileged section.
3.1.12 | Limit Users' SSH Access | By default, the SSH configuration allows any user with an account to access the system. In order to specify the users that are allowed to login via SSH and deny all other users, add or correct the following line in the `/etc/ssh/sshd_config` file:
    AllowUsers USER1 USER2
Where `USER1` and `USER2` are valid user names. | Specifying which accounts are allowed SSH access into the system reduces the possibility of unauthorized access to the system.
3.1.12 | Disable Kerberos Authentication | Unless needed, SSH should not permit extraneous or unnecessary authentication mechanisms like Kerberos. The default SSH configuration disallows authentication validation through Kerberos. The appropriate configuration is used if no value is set for `KerberosAuthentication`. To explicitly disable Kerberos authentication, add or correct the following line in `/etc/ssh/sshd_config`:
    KerberosAuthentication no
| Kerberos authentication for SSH is often implemented using GSSAPI. If Kerberos is enabled through SSH, the SSH daemon provides a means of access to the system's Kerberos implementation. Vulnerabilities in the system's Kerberos implementations may be subject to exploitation.
3.1.12 | Do Not Allow SSH Environment Options | Ensure that users are not able to override environment variables of the SSH daemon. The default SSH configuration disables environment processing. The appropriate configuration is used if no value is set for `PermitUserEnvironment`. To explicitly disable Environment options, add or correct the following `/etc/ssh/sshd_config`:
    PermitUserEnvironment no
| SSH environment options potentially allow users to bypass access restriction in some configurations.
3.1.12 | Disable SSH Support for Rhosts RSA Authentication | SSH can allow authentication through the obsolete rsh command through the use of the authenticating user's SSH keys. This should be disabled. To ensure this behavior is disabled, add or correct the following line in `/etc/ssh/sshd_config`:
    RhostsRSAAuthentication no
| Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.
3.1.12 | Disable GSSAPI Authentication | Unless needed, SSH should not permit extraneous or unnecessary authentication mechanisms like GSSAPI. The default SSH configuration disallows authentications based on GSSAPI. The appropriate configuration is used if no value is set for `GSSAPIAuthentication`. To explicitly disable GSSAPI authentication, add or correct the following line in `/etc/ssh/sshd_config`:
    GSSAPIAuthentication no
| GSSAPI authentication is used to provide additional authentication mechanisms to applications. Allowing GSSAPI authentication through SSH exposes the system's GSSAPI to remote hosts, increasing the attack surface of the system.
3.1.12 | Disable Compression Or Set Compression to delayed | Compression is useful for slow network connections over long distances but can cause performance issues on local LANs. If use of compression is required, it should be enabled only after a user has authenticated; otherwise, it should be disabled. To disable compression or delay compression until after a user has successfully authenticated, add or correct the following line in the `/etc/ssh/sshd_config` file:
    Compression no
| If compression is allowed in an SSH connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection, potentially with root privileges.
3.1.12 | Disable SSH Support for User Known Hosts | SSH can allow system users to connect to systems if a cache of the remote systems public keys is available. This should be disabled. To ensure this behavior is disabled, add or correct the following line in `/etc/ssh/sshd_config`:
    IgnoreUserKnownHosts yes
| Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.
3.1.13 | Require Encryption for Remote Access in GNOME3 | By default, `GNOME` requires encryption when using `Vino` for remote access. To prevent remote access encryption from being disabled, add or set `require-encryption` to `true` in `/etc/dconf/db/local.d/00-security-settings`. For example:
    [org/gnome/Vino]
    require-encryption=true
Once the settings have been added, add a lock to `/etc/dconf/db/local.d/locks/00-security-settings-lock` to prevent user modification. For example:
    /org/gnome/Vino/require-encryption
After the settings have been set, run `dconf update`. | Open X displays allow an attacker to capture keystrokes and to execute commands remotely.
3.1.13 3.4.7 | Disable rexec Service | The `rexec` service, which is available with the `rsh-server` package and runs as a service through xinetd or separately as a systemd socket, should be disabled. If using xinetd, set `disable` to `yes` in `/etc/xinetd.d/rexec`. The `rexec` socket can be disabled with the following command:
    $ sudo systemctl mask --now rexec.socket
| The rexec service uses unencrypted network communications, which means that data from the login session, including passwords and all other information transmitted during the session, can be stolen by eavesdroppers on the network.
3.1.13 3.13.10 | Verify Permissions on SSH Server Public *.pub Key Files | To properly set the permissions of `/etc/ssh/*.pub`, run the command:
    $ sudo chmod 0644 /etc/ssh/*.pub
| If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
3.1.13 | Remove telnet Clients | The telnet client allows users to start connections to other systems via the telnet protocol. | The `telnet` protocol is insecure and unencrypted. The use of an unencrypted transmission medium could allow an unauthorized user to steal credentials. The `ssh` package provides an encrypted session and stronger security and is included in Oracle Linux 7.
3.1.13 3.13.11 3.13.8 | Use Only FIPS 140-2 Validated Ciphers | Limit the ciphers to those algorithms which are FIPS-approved. Counter (CTR) mode is also preferred over cipher-block chaining (CBC) mode. The following line in `/etc/ssh/sshd_config` demonstrates use of FIPS-approved ciphers:
    Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc
The man page `sshd_config(5)` contains a list of supported ciphers. Only the following ciphers are FIPS 140-2 certified on Oracle Linux 7: - aes128-ctr - aes192-ctr - aes256-ctr - aes128-cbc - aes192-cbc - aes256-cbc - 3des-cbc - rijndael-cbc@lysator.liu.se Any combination of the above ciphers will pass this check. Official FIPS 140-2 paperwork for Oracle Linux 7 can be found at https://csrc.nist.gov/CSRC/media/projects/cryptographic-module-validation-program/documents/security-policies/140sp3028.pdf The rule is parametrized to use the following ciphers: ``aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se``. | Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied upon to provide confidentiality or integrity, and system data may be compromised. Operating systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets industry and government requirements. For government systems, this allows Security Levels 1, 2, 3, or 4 for use on Oracle Linux 7.
3.1.13 3.4.7 | Disable rsh Service | The `rsh` service, which is available with the `rsh-server` package and runs as a service through xinetd or separately as a systemd socket, should be disabled. If using xinetd, set `disable` to `yes` in `/etc/xinetd.d/rsh`. The `rsh` socket can be disabled with the following command:
    $ sudo systemctl mask --now rsh.socket
| The rsh service uses unencrypted network communications, which means that data from the login session, including passwords and all other information transmitted during the session, can be stolen by eavesdroppers on the network.
3.1.13 3.13.11 3.13.8 | Use Only FIPS 140-2 Validated MACs | Limit the MACs to those hash algorithms which are FIPS-approved. The following line in `/etc/ssh/sshd_config` demonstrates use of FIPS-approved MACs:
    MACs hmac-sha2-512,hmac-sha2-256,hmac-sha1
The man page `sshd_config(5)` contains a list of supported MACs. Only the following message authentication codes are FIPS 140-2 certified on Oracle Linux 7: - hmac-sha1 - hmac-sha2-256 - hmac-sha2-512 - hmac-sha1-etm@openssh.com - hmac-sha2-256-etm@openssh.com - hmac-sha2-512-etm@openssh.com Any combination of the above MACs will pass this check. Official FIPS 140-2 paperwork for Oracle Linux 7 can be found at https://csrc.nist.gov/CSRC/media/projects/cryptographic-module-validation-program/documents/security-policies/140sp3028.pdf The rule is parametrized to use the following MACs: ``hmac-sha2-512,hmac-sha2-256,hmac-sha1,hmac-sha1-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com``. | DoD Information Systems are required to use FIPS-approved cryptographic hash functions. The only SSHv2 hash algorithms meeting this requirement is SHA2.
3.1.13 3.4.7 | Disable telnet Service | The `telnet` service configuration file `/etc/xinetd.d/telnet` is not created automatically. If it was created manually, check the `/etc/xinetd.d/telnet` file and ensure that `disable = no` is changed to read `disable = yes` as follows below:
    # description: The telnet server serves telnet sessions; it uses \\
    #       unencrypted username/password pairs for authentication.
    service telnet
    {
            flags           = REUSE
            socket_type     = stream

            wait            = no
            user            = root
            server          = /usr/sbin/in.telnetd
            log_on_failure  += USERID
            disable         = yes
    }
If the `/etc/xinetd.d/telnet` file does not exist, make sure that the activation of the `telnet` service on system boot is disabled via the following command: The `rexec` socket can be disabled with the following command:
    $ sudo systemctl mask --now rexec.socket
| The telnet protocol uses unencrypted network communication, which means that data from the login session, including passwords and all other information transmitted during the session, can be stolen by eavesdroppers on the network. The telnet protocol is also subject to man-in-the-middle attacks.
3.1.13 | Uninstall rsh Package | The `rsh` package contains the client commands for the rsh services | These legacy clients contain numerous security exposures and have been replaced with the more secure SSH package. Even if the server is removed, it is best to ensure the clients are also removed to prevent users from inadvertently attempting to use these commands and therefore exposing their credentials. Note that removing the `rsh` package removes the clients for `rsh`,`rcp`, and `rlogin`.
3.1.13 3.4.7 | Disable rlogin Service | The `rlogin` service, which is available with the `rsh-server` package and runs as a service through xinetd or separately as a systemd socket, should be disabled. If using xinetd, set `disable` to `yes` in `/etc/xinetd.d/rlogin`. The `rlogin` socket can be disabled with the following command:
    $ sudo systemctl mask --now rlogin.socket
| The rlogin service uses unencrypted network communications, which means that data from the login session, including passwords and all other information transmitted during the session, can be stolen by eavesdroppers on the network.
3.1.13 3.13.10 | Verify Permissions on SSH Server Private *_key Key Files | To properly set the permissions of `/etc/ssh/*_key`, run the command:
    $ sudo chmod 0600 /etc/ssh/*_key
| If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
3.1.13 | Enable Encrypted X11 Forwarding | By default, remote X11 connections are not encrypted when initiated by users. SSH has the capability to encrypt remote X11 connections when SSH's `X11Forwarding` option is enabled. To enable X11 Forwarding, add or correct the following line in `/etc/ssh/sshd_config`:
    X11Forwarding yes
| Non-encrypted X displays allow an attacker to capture keystrokes and to execute commands remotely.
3.1.13 3.5.4 | Allow Only SSH Protocol 2 | Only SSH protocol version 2 connections should be permitted. The default setting in `/etc/ssh/sshd_config` is correct, and can be verified by ensuring that the following line appears:
    Protocol 2
| SSH protocol version 1 is an insecure implementation of the SSH protocol and has many well-known vulnerability exploits. Exploits of the SSH daemon could provide immediate root access to the system.
3.1.13 3.5.4 3.13.8 | Enable the OpenSSH Service | The SSH server service, sshd, is commonly needed. The `sshd` service can be enabled with the following command:
    $ sudo systemctl enable sshd.service
| Without protection of the transmitted information, confidentiality, and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This checklist item applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, etc). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification.
3.1.16 | Disable Bluetooth Kernel Module | The kernel's module loading system can be configured to prevent loading of the Bluetooth module. Add the following to the appropriate `/etc/modprobe.d` configuration file to prevent the loading of the Bluetooth module:
    install bluetooth /bin/true
| If Bluetooth functionality must be disabled, preventing the kernel from loading the kernel module provides an additional safeguard against its activation.
3.1.16 | Deactivate Wireless Network Interfaces | Deactivating wireless network interfaces should prevent normal usage of the wireless capability. Configure the system to disable all wireless network interfaces with the following command:
    $ sudo nmcli radio wifi off
| The use of wireless networking can introduce many different attack vectors into the organization's network. Common attack vectors such as malicious association and ad hoc networks will allow an attacker to spoof a wireless access point (AP), allowing validated systems to connect to the malicious AP and enabling the attacker to monitor and record network traffic. These malicious APs can also serve to create a man-in-the-middle attack or be used to create a denial of service to valid network resources.
3.1.20 | Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces | To set the runtime status of the `net.ipv4.conf.default.accept_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.accept_redirects = 0
| ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required.
3.1.20 | Disable IPv6 Addressing on All IPv6 Interfaces | To disable support for (`ipv6`) addressing on all interface add the following line to `/etc/sysctl.d/ipv6.conf` (or another file in `/etc/sysctl.d`):
    net.ipv6.conf.all.disable_ipv6 = 1
This disables IPv6 on all network interfaces as other services and system functionality require the IPv6 stack loaded to work. | Any unnecessary network stacks - including IPv6 - should be disabled, to reduce the vulnerability to exploitation.
3.1.20 | Configure Accepting Router Advertisements on All IPv6 Interfaces | To set the runtime status of the `net.ipv6.conf.all.accept_ra` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.all.accept_ra=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.all.accept_ra = 0
| An illicit router advertisement message could result in a man-in-the-middle attack.
3.1.20 | Enable Kernel Parameter to Use TCP Syncookies on IPv4 Interfaces | To set the runtime status of the `net.ipv4.tcp_syncookies` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.tcp_syncookies=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.tcp_syncookies = 1
| A TCP SYN flood attack can cause a denial of service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected, and enables the system to continue servicing valid connection requests.
3.1.20 | Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces | To set the runtime status of the `net.ipv4.icmp_ignore_bogus_error_responses` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.icmp_ignore_bogus_error_responses = 1
| Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged.
3.1.20 | Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces | To set the runtime status of the `net.ipv4.conf.all.secure_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.secure_redirects = 0
| Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.
3.1.20 | Disable Accepting ICMP Redirects for All IPv4 Interfaces | To set the runtime status of the `net.ipv4.conf.all.accept_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.accept_redirects = 0
| ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required."
3.1.20 | Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces by Default | To set the runtime status of the `net.ipv4.conf.default.accept_source_route` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.accept_source_route = 0
| Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required, such as when IPv4 forwarding is enabled and the system is legitimately functioning as a router.
3.1.20 | Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces | To set the runtime status of the `net.ipv4.conf.all.accept_source_route` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.accept_source_route = 0
| Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv4 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
3.1.20 | Disable IPv6 Addressing on IPv6 Interfaces by Default | To disable support for (`ipv6`) addressing on interfaces by default add the following line to `/etc/sysctl.d/ipv6.conf` (or another file in `/etc/sysctl.d`):
    net.ipv6.conf.default.disable_ipv6 = 1
This disables IPv6 on network interfaces by default as other services and system functionality require the IPv6 stack loaded to work. | Any unnecessary network stacks - including IPv6 - should be disabled, to reduce the vulnerability to exploitation.
3.1.20 | Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces | To set the runtime status of the `net.ipv4.icmp_echo_ignore_broadcasts` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.icmp_echo_ignore_broadcasts = 1
| Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks. Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network.
3.1.20 | Use Privacy Extensions for Address | To introduce randomness into the automatic generation of IPv6 addresses, add or correct the following line in `/etc/sysconfig/network-scripts/ifcfg-interface`:
    IPV6_PRIVACY=rfc3041
Automatically-generated IPv6 addresses are based on the underlying hardware (e.g. Ethernet) address, and so it becomes possible to track a piece of hardware over its lifetime using its traffic. If it is important for a system's IP address to not trivially reveal its hardware address, this setting should be applied. |
3.1.20 | Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces | To set the runtime status of the `net.ipv4.conf.all.log_martians` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.log_martians = 1
| The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.
3.1.20 | Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Default | To set the runtime status of the `net.ipv6.conf.default.accept_source_route` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.default.accept_source_route = 0
| Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
3.1.20 | Disable Accepting ICMP Redirects for All IPv6 Interfaces | To set the runtime status of the `net.ipv6.conf.all.accept_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.all.accept_redirects = 0
| An illicit ICMP redirect message could result in a man-in-the-middle attack.
3.1.20 | Disable Accepting Router Advertisements on all IPv6 Interfaces by Default | To set the runtime status of the `net.ipv6.conf.default.accept_ra` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.default.accept_ra=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.default.accept_ra = 0
| An illicit router advertisement message could result in a man-in-the-middle attack.
3.1.20 | Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces | To set the runtime status of the `net.ipv6.conf.default.accept_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.default.accept_redirects = 0
| An illicit ICMP redirect message could result in a man-in-the-middle attack.
3.1.20 | Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces | To set the runtime status of the `net.ipv4.ip_forward` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.ip_forward=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.ip_forward = 0
| Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this capability is used when not required, system network information may be unnecessarily transmitted across the network.
3.1.20 | Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces | To set the runtime status of the `net.ipv4.conf.all.rp_filter` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.rp_filter = 1
| Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
3.1.20 | Configure Kernel Parameter for Accepting Secure Redirects By Default | To set the runtime status of the `net.ipv4.conf.default.secure_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.secure_redirects = 0
| Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.
3.1.20 | Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces | To set the runtime status of the `net.ipv4.conf.all.send_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.send_redirects = 0
| ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology. The ability to send ICMP redirects is only appropriate for systems acting as routers.
3.1.20 | Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces by Default | To set the runtime status of the `net.ipv4.conf.default.rp_filter` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.rp_filter = 1
| Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
3.1.20 | Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces by Default | To set the runtime status of the `net.ipv4.conf.default.send_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.send_redirects = 0
| ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology. The ability to send ICMP redirects is only appropriate for systems acting as routers.
3.1.20 | Enable Kernel Paremeter to Log Martian Packets on all IPv4 Interfaces by Default | To set the runtime status of the `net.ipv4.conf.default.log_martians` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.log_martians = 1
| The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.
3.1.20 | Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces | To set the runtime status of the `net.ipv6.conf.all.accept_source_route` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.all.accept_source_route = 0
| Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
3.1.21 | Disable Modprobe Loading of USB Storage Driver | To prevent USB storage devices from being used, configure the kernel module loading system to prevent automatic loading of the USB storage driver. To configure the system to prevent the `usb-storage` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:
    install usb-storage /bin/true
This will prevent the `modprobe` program from loading the `usb-storage` module, but will not prevent an administrator (or another program) from using the `insmod` program to load the module manually. | USB storage devices such as thumb drives can be used to introduce malicious software.
3.3.1 | Configure auditd flush priority | The `auditd` service can be configured to synchronously write audit event data to disk. Add or correct the following line in `/etc/audit/auditd.conf` to ensure that audit event data is fully synchronized with the log files on the disk:
    flush = data
| Audit data should be synchronously written to disk to ensure log integrity. These parameters assure that all audit event data is fully synchronized with the log files on the disk.
3.3.1 | Configure auditd space_left Action on Low Disk Space | The `auditd` service can be configured to take an action when disk space starts to run low. Edit the file `/etc/audit/auditd.conf`. Modify the following line, substituting ACTION appropriately:
    space_left_action = ACTION
Possible values for ACTION are described in the `auditd.conf` man page. These include: `syslog` `email` `exec` `suspend` `single` `halt` Set this to `email` (instead of the default, which is `suspend`) as it is more likely to get prompt attention. Acceptable values also include `suspend`, `single`, and `halt`. | Notifying administrators of an impending disk space problem may allow them to take corrective action prior to any disruption.
3.3.1 | Configure auditd Number of Logs Retained | Determine how many log files `auditd` should retain when it rotates logs. Edit the file `/etc/audit/auditd.conf`. Add or modify the following line, substituting NUMLOGS with the correct value of `5`:
    num_logs = NUMLOGS
Set the value to 5 for general-purpose systems. Note that values less than 2 result in no log rotation. | The total storage for audit log files must be large enough to retain log information over the period required. This is a function of the maximum log file size and the number of logs retained.
3.3.1 | Configure auditd to use audispd's syslog plugin | To configure the `auditd` service to use the `syslog` plug-in of the `audispd` audit event multiplexor, set the `active` line in `/etc/audisp/plugins.d/syslog.conf` to `yes`. Restart the `auditd` service:
    $ sudo service auditd restart
| The auditd service does not include the ability to send audit records to a centralized server for management directly. It does, however, include a plug-in for audit event multiplexor (audispd) to pass audit records to the local syslog server
3.3.1 | Configure auditd admin_space_left Action on Low Disk Space | The `auditd` service can be configured to take an action when disk space is running low but prior to running out of space completely. Edit the file `/etc/audit/auditd.conf`. Add or modify the following line, substituting ACTION appropriately:
    admin_space_left_action = ACTION
Set this value to `single` to cause the system to switch to single user mode for corrective action. Acceptable values also include `suspend` and `halt`. For certain systems, the need for availability outweighs the need to log all actions, and a different setting should be determined. Details regarding all possible values for ACTION are described in the `auditd.conf` man page. | Administrators should be made aware of an inability to record audit records. If a separate partition or logical volume of adequate size is used, running low on space for audit records should never occur.
3.3.1 3.4.3 | Make the auditd Configuration Immutable | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d` in order to make the auditd configuration immutable:
    -e 2
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file in order to make the auditd configuration immutable:
    -e 2
With this setting, a reboot will be required to change any audit rules. | Making the audit configuration immutable prevents accidental as well as malicious modification of the audit rules, although it may be problematic if legitimate changes are needed during system operation
3.3.1 | Configure auditd mail_acct Action on Low Disk Space | The `auditd` service can be configured to send email to a designated account in certain situations. Add or correct the following line in `/etc/audit/auditd.conf` to ensure that administrators are notified via email for those situations:
    action_mail_acct = root
| Email sent to the root account is typically aliased to the administrators of the system, who can take appropriate action.
3.3.1 | Enable Auditing for Processes Which Start Prior to the Audit Daemon | To ensure all processes can be audited, even those which start prior to the audit daemon, add the argument `audit=1` to the default GRUB 2 command line for the Linux operating system. To ensure that `audit=1` is added as a kernel command line argument to newly installed kernels, ad `audit=1` to the default Grub2 command line for Linux operating systems. Modify the line within `/etc/default/grub` as shown below:
    GRUB_CMDLINE_LINUX="... audit=1 ..."
Run the following command to update command line for already installed kernels:
    # grubby --update-kernel=ALL --args="audit=1"
| Each process on the system carries an "auditable" flag which indicates whether its activities can be audited. Although `auditd` takes care of enabling this for all processes which launch after it does, adding the kernel argument ensures it is set for every process during boot.
3.3.1 3.3.4 | Shutdown System When Auditing Failures Occur | If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -f 2
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to the top of the `/etc/audit/audit.rules` file:
    -f 2
| It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded.
3.3.1 | System Audit Logs Must Have Mode 0640 or Less Permissive | If `log_group` in `/etc/audit/auditd.conf` is set to a group other than the `root` group account, change the mode of the audit log files with the following command:
    $ sudo chmod 0640 audit_file
Otherwise, change the mode of the audit log files with the following command:
    $ sudo chmod 0600 audit_file
| If users can write to audit logs, audit trails can be modified or destroyed.
3.3.1 | System Audit Logs Must Be Owned By Root | All audit logs must be owned by root user and group. By default, the path for audit log is
    /var/log/audit/
. To properly set the owner of `/var/log/audit`, run the command:
    $ sudo chown root /var/log/audit
To properly set the owner of `/var/log/audit/*`, run the command:
    $ sudo chown root /var/log/audit/*
| Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality.
3.3.1 3.3.2 3.3.6 | Enable auditd Service | The `auditd` service is an essential userspace component of the Linux Auditing System, as it is responsible for writing audit records to disk. The `auditd` service can be enabled with the following command:
    $ sudo systemctl enable auditd.service
| Without establishing what type of events occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Ensuring the `auditd` service is active ensures audit records generated by the kernel are appropriately recorded. Additionally, a properly configured audit subsystem ensures that actions of individual system users can be uniquely traced to those users so they can be held accountable for their actions.
3.3.7 | Specify a Remote NTP Server | Depending on specific functional requirements of a concrete production environment, the Oracle Linux 7 system can be configured to utilize the services of the `chronyd` NTP daemon (the default), or services of the `ntpd` NTP daemon. Refer to https://docs.oracle.com/en/operating-systems/oracle-linux/7/network/ol7-nettime.html for more detailed comparison of the features of both of the choices, and for further guidance how to choose between the two NTP daemons. To specify a remote NTP server for time synchronization, perform the following: if the system is configured to use the `chronyd` as the NTP daemon (the default), edit the file `/etc/chrony.conf` as follows, if the system is configured to use the `ntpd` as the NTP daemon, edit the file `/etc/ntp.conf` as documented below. Add or correct the following lines, substituting the IP or hostname of a remote NTP server for ntpserver:
    server ntpserver
This instructs the NTP software to contact that remote server to obtain time data. | Synchronizing with an NTP server makes it possible to collate system logs from multiple sources or correlate computer events with real time events.
3.3.7 | Enable the NTP Daemon | Run the following command to determine the current status of the `chronyd` service:
    $ systemctl is-active chronyd
If the service is running, it should return the following:
    active
Note: The `chronyd` daemon is enabled by default. Run the following command to determine the current status of the `ntpd` service:
    $ systemctl is-active ntpd
If the service is running, it should return the following:
    active
Note: The `ntpd` daemon is not enabled by default. Though as mentioned in the previous sections in certain environments the `ntpd` daemon might be preferred to be used rather than the `chronyd` one. Refer to: https://docs.oracle.com/en/operating-systems/oracle-linux/7/network/ol7-nettime.html for guidance which NTP daemon to choose depending on the environment used. | Enabling some of `chronyd` or `ntpd` services ensures that the NTP daemon will be running and that the system will synchronize its time to any servers specified. This is important whether the system is configured to be a client (and synchronize only its own clock) or it is also acting as an NTP server to other systems. Synchronizing time is essential for authentication services such as Kerberos, but it is also important for maintaining accurate logs and auditing possible security breaches. The `chronyd` and `ntpd` NTP daemons offer all of the functionality of `ntpdate`, which is now deprecated.
3.3.8 3.4.1 | Verify File Hashes with RPM | Without cryptographic integrity protections, system executables and files can be altered by unauthorized users without detection. The RPM package management system can check the hashes of installed software packages, including many that are important to system security. To verify that the cryptographic hash of system files and commands matches vendor values, run the following command to list which files on the system have hashes that differ from what is expected by the RPM database:
    $ rpm -Va --noconfig | grep '^..5'
A "c" in the second column indicates that a file is a configuration file, which may appropriately be expected to change. If the file was not expected to change, investigate the cause of the change using audit logs or other means. The package can then be reinstalled to restore the file. Run the following command to determine which package owns the file:
    $ rpm -qf FILENAME
The package can be reinstalled from a yum repository using the command:
    $ sudo yum reinstall PACKAGENAME
Alternatively, the package can be reinstalled from trusted media using the command:
    $ sudo rpm -Uvh PACKAGENAME
| The hashes of important files like system executables should match the information given by the RPM database. Executables with erroneous hashes could be a sign of nefarious activity on the system.
3.3.8 3.4.1 | Verify and Correct File Permissions with RPM | The RPM package management system can check file access permissions of installed software packages, including many that are important to system security. Verify that the file permissions of system files and commands match vendor values. Check the file permissions with the following command:
    $ sudo rpm -Va | awk '{ if (substr($0,2,1)=="M") print $NF }'
Output indicates files that do not match vendor defaults. After locating a file with incorrect permissions, run the following command to determine which package owns it:
    $ rpm -qf FILENAME
Next, run the following command to reset its permissions to the correct values:
    $ sudo rpm --setperms PACKAGENAME
| Permissions on system binaries and configuration files that are too generous could allow an unauthorized user to gain privileges that they should not have. The permissions set by the vendor should be maintained. Any deviations from this baseline should be investigated.
3.3.8 3.4.1 | Verify and Correct Ownership with RPM | The RPM package management system can check file ownership permissions of installed software packages, including many that are important to system security. After locating a file with incorrect permissions, which can be found with
    rpm -Va | awk '{ if (substr($0,6,1)=="U" || substr($0,7,1)=="G") print $NF }'
run the following command to determine which package owns it:
    $ rpm -qf FILENAME
Next, run the following command to reset its permissions to the correct values:
    $ sudo rpm --setugids PACKAGENAME
| Ownership of binaries and configuration files that is incorrect could allow an unauthorized user to gain privileges that they should not have. The ownership set by the vendor should be maintained. Any deviations from this baseline should be investigated.
3.4.5 | Verify /boot/grub2/grub.cfg Permissions | File permissions for `/boot/grub2/grub.cfg` should be set to 600. To properly set the permissions of `/boot/grub2/grub.cfg`, run the command:
    $ sudo chmod 600 /boot/grub2/grub.cfg
| Proper permissions ensure that only the root user can modify important boot parameters.
3.4.5 | Disable Ctrl-Alt-Del Burst Action | By default, `SystemD` will reboot the system if the `Ctrl-Alt-Del` key sequence is pressed Ctrl-Alt-Delete more than 7 times in 2 seconds. To configure the system to ignore the `CtrlAltDelBurstAction` setting, add or modify the following to `/etc/systemd/system.conf`:
    CtrlAltDelBurstAction=none
| A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.
3.4.5 | Verify /boot/grub2/grub.cfg Group Ownership | The file `/boot/grub2/grub.cfg` should be group-owned by the `root` group to prevent destruction or modification of the file. To properly set the group owner of `/boot/grub2/grub.cfg`, run the command:
    $ sudo chgrp root /boot/grub2/grub.cfg
| The `root` group is a highly-privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway.
3.4.5 | Verify the UEFI Boot Loader grub.cfg Permissions | File permissions for `/boot/efi/EFI/redhat/grub.cfg` should be set to 700. To properly set the permissions of `/boot/efi/EFI/redhat/grub.cfg`, run the command:
    $ sudo chmod 700 /boot/efi/EFI/redhat/grub.cfg
| Proper permissions ensure that only the root user can modify important boot parameters.
3.4.5 | Disable Ctrl-Alt-Del Reboot Activation | By default, `SystemD` will reboot the system if the `Ctrl-Alt-Del` key sequence is pressed. To configure the system to ignore the `Ctrl-Alt-Del` key sequence from the command line instead of rebooting the system, do either of the following:
    ln -sf /dev/null /etc/systemd/system/ctrl-alt-del.target
or
    systemctl mask ctrl-alt-del.target
Do not simply delete the `/usr/lib/systemd/system/ctrl-alt-del.service` file, as this file may be restored during future system updates. | A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.
3.4.5 | Verify the UEFI Boot Loader grub.cfg Group Ownership | The file `/boot/efi/EFI/redhat/grub.cfg` should be group-owned by the `root` group to prevent destruction or modification of the file. To properly set the group owner of `/boot/efi/EFI/redhat/grub.cfg`, run the command:
    $ sudo chgrp root /boot/efi/EFI/redhat/grub.cfg
| The `root` group is a highly-privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway.
3.4.5 | Set the Boot Loader Admin Username to a Non-Default Value | The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings. To maximize the protection, select a password-protected superuser account with unique name, and modify the `/etc/grub.d/01_users` configuration file to reflect the account name change. Do not to use common administrator account names like root, admin, or administrator for the grub2 superuser account. Change the superuser to a different username (The default is 'root').
    $ sed -i 's/\(set superuser=\).*/\1"<unique user ID>"/g' /etc/grub.d/01_users
Once the superuser account has been added, update the `grub.cfg` file by running:
    grub2-mkconfig -o /boot/grub2/grub.cfg
| Having a non-default grub superuser username makes password-guessing attacks less effective.
3.4.5 | Verify /boot/grub2/grub.cfg User Ownership | The file `/boot/grub2/grub.cfg` should be owned by the `root` user to prevent destruction or modification of the file. To properly set the owner of `/boot/grub2/grub.cfg`, run the command:
    $ sudo chown root /boot/grub2/grub.cfg
| Only root should be able to modify important boot parameters.
3.4.5 | Verify the UEFI Boot Loader grub.cfg User Ownership | The file `/boot/efi/EFI/redhat/grub.cfg` should be owned by the `root` user to prevent destruction or modification of the file. To properly set the owner of `/boot/efi/EFI/redhat/grub.cfg`, run the command:
    $ sudo chown root /boot/efi/EFI/redhat/grub.cfg
| Only root should be able to modify important boot parameters.
3.4.5 | Disable debug-shell SystemD Service | SystemD's `debug-shell` service is intended to diagnose SystemD related boot issues with various `systemctl` commands. Once enabled and following a system reboot, the root shell will be available on `tty9` which is access by pressing `CTRL-ALT-F9`. The `debug-shell` service should only be used for SystemD related issues and should otherwise be disabled. By default, the `debug-shell` SystemD service is already disabled. The `debug-shell` service can be disabled with the following command:
    $ sudo systemctl mask --now debug-shell.service
| This prevents attackers with physical access from trivially bypassing security on the machine through valid troubleshooting configurations and gaining root access when the system is rebooted.
3.4.5 | Set the UEFI Boot Loader Password | The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings. Since plaintext passwords are a security risk, generate a hash for the password by running the following command:
    # grub2-setpassword
When prompted, enter the password that was selected. | Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.
3.4.5 | Set the UEFI Boot Loader Admin Username to a Non-Default Value | The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings. To maximize the protection, select a password-protected superuser account with unique name, and modify the `/etc/grub.d/01_users` configuration file to reflect the account name change. It is highly suggested not to use common administrator account names like root, admin, or administrator for the grub2 superuser account. Change the superuser to a different username (The default is 'root').
    $ sed -i 's/\(set superuser=\).*/\1"<unique user ID>"/g' /etc/grub.d/01_users
Once the superuser account has been added, update the `grub.cfg` file by running:
    grub2-mkconfig -o /boot/grub2/grub.cfg
| Having a non-default grub superuser username makes password-guessing attacks less effective.
3.4.5 | Set Boot Loader Password in grub2 | The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings. Since plaintext passwords are a security risk, generate a hash for the password by running the following command:
    # grub2-setpassword
When prompted, enter the password that was selected. | Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.
3.4.6 | Disable DCCP Support | The Datagram Congestion Control Protocol (DCCP) is a relatively new transport layer protocol, designed to support streaming media and telephony. To configure the system to prevent the `dccp` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:
    install dccp /bin/true
| Disabling DCCP protects the system against exploitation of any flaws in its implementation.
3.4.6 | Disable SCTP Support | The Stream Control Transmission Protocol (SCTP) is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. To configure the system to prevent the `sctp` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:
    install sctp /bin/true
| Disabling SCTP protects the system against exploitation of any flaws in its implementation.
3.4.6 | Disable Mounting of cramfs | To configure the system to prevent the `cramfs` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:
    install cramfs /bin/true
This effectively prevents usage of this uncommon filesystem. The `cramfs` filesystem type is a compressed read-only Linux filesystem embedded in small footprint systems. A `cramfs` image can be used without having to first decompress the image. | Removing support for unneeded filesystem types reduces the local attack surface of the server.
3.4.6 | Disable the Automounter | The `autofs` daemon mounts and unmounts filesystems, such as user home directories shared via NFS, on demand. In addition, autofs can be used to handle removable media, and the default configuration provides the cdrom device as `/misc/cd`. However, this method of providing access to removable media is not common, so autofs can almost always be disabled if NFS is not in use. Even if NFS is required, it may be possible to configure filesystem mounts statically by editing `/etc/fstab` rather than relying on the automounter. The `autofs` service can be disabled with the following command:
    $ sudo systemctl mask --now autofs.service
| Disabling the automounter permits the administrator to statically control filesystem mounting through `/etc/fstab`. Additionally, automatically mounting filesystems permits easy introduction of unknown devices, thereby facilitating malicious activity.
3.4.7 | Disable xinetd Service | The `xinetd` service can be disabled with the following command:
    $ sudo systemctl mask --now xinetd.service
| The xinetd service provides a dedicated listener service for some programs, which is no longer necessary for commonly-used network services. Disabling it ensures that these uncommon services are not running, and also prevents attacks against xinetd itself.
3.4.8 | Ensure gpgcheck Enabled for Local Packages | `yum` should be configured to verify the signature(s) of local packages prior to installation. To configure `yum` to verify signatures of local packages, set the `localpkg_gpgcheck` to `1` in `/etc/yum.conf`. | Changes to any software components can have significant effects to the overall security of the operating system. This requirement ensures the software has not been tampered and has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization.
3.4.8 | Ensure gpgcheck Enabled In Main yum Configuration | The `gpgcheck` option controls whether RPM packages' signatures are always checked prior to installation. To configure yum to check package signatures before installing them, ensure the following line appears in `/etc/yum.conf` in the `[main]` section:
    gpgcheck=1
| Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. Certificates used to verify the software must be from an approved Certificate Authority (CA).
3.4.8 | Ensure yum Removes Previous Package Versions | `yum` should be configured to remove previous software components after new versions have been installed. To configure `yum` to remove the previous software components after updating, set the `clean_requirements_on_remove` to `1` in `/etc/yum.conf`. | Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by some adversaries.
3.4.8 | Ensure gpgcheck Enabled for All yum Package Repositories | To ensure signature checking is not disabled for any repos, remove any lines from files in `/etc/yum.repos.d` of the form:
    gpgcheck=0
| Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. Certificates used to verify the software must be from an approved Certificate Authority (CA)."
3.5.6 | Set Password Maximum Age | To specify password maximum age for new accounts, edit the file `/etc/login.defs` and add or correct the following line:
    PASS_MAX_DAYS 60
A value of 180 days is sufficient for many environments. The DoD requirement is 60. The profile requirement is ``60``. | Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised. Setting the password maximum age ensures users are required to periodically change their passwords. Requiring shorter password lifetimes increases the risk of users writing down the password in a convenient location subject to physical compromise.
3.5.6 | Set Account Expiration Following Inactivity | To specify the number of days after a password expires (which signifies inactivity) until an account is permanently disabled, add or correct the following line in `/etc/default/useradd`:
    INACTIVE=35
If a password is currently on the verge of expiration, then ``35`` day(s) remain(s) until the account is automatically disabled. However, if the password will not expire for another 60 days, then 60 days plus ``35`` day(s) could elapse until the account would be automatically disabled. See the `useradd` man page for more information. | Disabling inactive accounts ensures that accounts which may not have been responsibly removed are not available to attackers who may have compromised their credentials.
3.5.7 | Set Password Minimum Length in login.defs | To specify password length requirements for new accounts, edit the file `/etc/login.defs` and add or correct the following line:
    PASS_MIN_LEN 15
The DoD requirement is `15`. The FISMA requirement is `12`. The profile requirement is ``15``. If a program consults `/etc/login.defs` and also another PAM module (such as `pam_pwquality`) during a password change operation, then the most restrictive must be satisfied. See PAM section for more information about enforcing password quality requirements. | Requiring a minimum password length makes password cracking attacks more difficult by ensuring a larger search space. However, any security benefit from an onerous requirement must be carefully weighed against usability problems, support costs, or counterproductive behavior that may result.
3.5.8 | Limit Password Reuse: password-auth | Do not allow users to reuse recent passwords. This can be accomplished by using the `remember` option for the `pam_pwhistory` PAM modules. In the file `/etc/pam.d/password-auth`, make sure the parameter `remember` is present, and that the value for the `remember` parameter is `5` or greater. For example:
    password requisite pam_pwhistory.so ...existing_options... remember=5 use_authtok
The DoD STIG requirement is 5 passwords. | Preventing re-use of previous passwords helps ensure that a compromised password is not re-used by a user.
- 3.5.8 | Limit Password Reuse | Do not allow users to reuse recent passwords. This can be accomplished by using the `remember` option for the `pam_unix` or `pam_pwhistory` PAM modules. In the file `/etc/pam.d/system-auth`, append `remember=`5`` to the line which refers to the `pam_unix.so` or `pam_pwhistory.so`module, as shown below: for the `pam_unix.so` case:
      password sufficient pam_unix.so ...existing_options... remember=5
- for the `pam_pwhistory.so` case:
      password requisite pam_pwhistory.so ...existing_options... remember=5
The DoD STIG requirement is 5 passwords. | Preventing re-use of previous passwords helps ensure that a compromised password is not re-used by a user.
3.5.8 | Set Password Minimum Age | To specify password minimum age for new accounts, edit the file `/etc/login.defs` and add or correct the following line:
    PASS_MIN_DAYS 7
A value of 1 day is considered sufficient for many environments. The DoD requirement is 1. The profile requirement is ``7``. | Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, then the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse. Setting the minimum password age protects against users cycling back to a favorite password after satisfying the password reuse requirement.
3.5.8 | Set Password Warning Age | To specify how many days prior to password expiration that a warning will be issued to users, edit the file `/etc/login.defs` and add or correct the following line:
    PASS_WARN_AGE 7
The DoD requirement is 7. The profile requirement is ``7``. | Setting the password warning age enables users to make the change at a practical time.
3.5.8 | Limit Password Reuse: system-auth | Do not allow users to reuse recent passwords. This can be accomplished by using the `remember` option for the `pam_pwhistory` PAM modules. In the file `/etc/pam.d/system-auth`, make sure the parameter `remember` is present, and that the value for the `remember` parameter is `5` or greater. For example:
    password requisite pam_pwhistory.so ...existing_options... remember=5 use_authtok
The DoD STIG requirement is 5 passwords. | Preventing re-use of previous passwords helps ensure that a compromised password is not re-used by a user.
3.5.10 | Verify All Account Password Hashes are Shadowed | If any password hashes are stored in `/etc/passwd` (in the second field, instead of an `x` or `*`), the cause of this misconfiguration should be investigated. The account should have its password reset and the hash should be properly stored, or the account should be deleted entirely. | The hashes for all user account passwords should be stored in the file `/etc/shadow` and never in `/etc/passwd`, which is readable by all users.
3.13.8 3.13.11 | Enable FIPS Mode in GRUB2 | To ensure FIPS mode is enabled, install package `dracut-fips`, and rebuild `initramfs` by running the following commands:
    $ sudo yum install dracut-fips
    dracut -f
After the `dracut` command has been run, add the argument `fips=1` to the default GRUB 2 command line for the Linux operating system in `/etc/default/grub`, in the manner below:
    GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=VolGroup/LogVol06 rd.lvm.lv=VolGroup/lv_swap rhgb quiet rd.shell=0 fips=1"
Finally, rebuild the `grub.cfg` file by using the
    grub2-mkconfig -o
- command as follows: On BIOS-based machines, issue the following command as `root`:
      ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
- On UEFI-based machines, issue the following command as `root`:
      ~]# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
| Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated.
3.13.11 | Set Password Hashing Algorithm in /etc/libuser.conf | In `/etc/libuser.conf`, add or correct the following line in its `[defaults]` section to ensure the system will use the SHA-512 algorithm for password hashing:
    crypt_style = sha512
| Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kepy in plain text. This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the `crypt_style` configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.
3.13.11 | Set PAM's Password Hashing Algorithm | The PAM system service can be configured to only store encrypted representations of passwords. In `/etc/pam.d/system-auth`, the `password` section of the file controls which PAM modules execute during a password change. Set the `pam_unix.so` module in the `password` section to include the argument `sha512`, as shown below:
    password    sufficient    pam_unix.so sha512 other arguments...
This will help ensure when local users change their passwords, hashes for the new passwords will be generated using the SHA-512 algorithm. This is the default. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kepy in plain text. This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the `crypt_style` configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.
3.13.11 | Set Password Hashing Algorithm in /etc/login.defs | In `/etc/login.defs`, add or correct the following line to ensure the system will use SHA-512 as the hashing algorithm:
    ENCRYPT_METHOD SHA512
| Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. Using a stronger hashing algorithm makes password cracking attacks more difficult.
3.13.11 3.13.8 | Install the dracut-fips-aesni Package | To enable FIPS on system that support the Advanced Encryption Standard (AES) or New Instructions (AES-NI) engine, the system requires that the `dracut-fips-aesni` package be installed. The `dracut-fips-aesni` package can be installed with the following command:
    $ sudo yum install dracut-fips-aesni
| Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated.
3.13.11 3.13.8 | Install the dracut-fips Package | To enable FIPS, the system requires that the `dracut-fips` package be installed. The `dracut-fips` package can be installed with the following command:
    $ sudo yum install dracut-fips
| Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated.
3.13.11 | Configure AIDE to Use FIPS 140-2 for Validating Hashes | By default, the `sha512` option is added to the `NORMAL` ruleset in AIDE. If using a custom ruleset or the `sha512` option is missing, add `sha512` to the appropriate ruleset. For example, add `sha512` to the following line in `/etc/aide.conf`:
    NORMAL = FIPSR+sha512
AIDE rules can be configured in multiple ways; this is merely one example that is already configured by default. | File integrity tools use cryptographic hashes for verifying file contents and directories have not been altered. These hashes must be FIPS 140-2 approved cryptographic hashes.
3.13.11 | Disable Prelinking | The prelinking feature changes binaries in an attempt to decrease their startup time. In order to disable it, change or add the following line inside the file `/etc/sysconfig/prelink`:
    PRELINKING=no
Next, run the following command to return binaries to a normal, non-prelinked state:
    $ sudo /usr/sbin/prelink -ua
| Because the prelinking feature changes binaries, it can interfere with the operation of certain software and/or modes such as AIDE, FIPS, etc.
3.13.16 | Encrypt Partitions | Oracle Linux 7 natively supports partition encryption through the Linux Unified Key Setup-on-disk-format (LUKS) technology. The easiest way to encrypt a partition is during installation time. For manual installations, select the `Encrypt` checkbox during partition creation to encrypt the partition. When this option is selected the system will prompt for a passphrase to use in decrypting the partition. The passphrase will subsequently need to be entered manually every time the system boots. For automated/unattended installations, it is possible to use Kickstart by adding the `--encrypted` and `--passphrase=` options to the definition of each partition to be encrypted. For example, the following line would encrypt the root partition:
    part / --fstype=ext4 --size=100 --onpart=hda1 --encrypted --passphrase=PASSPHRASE
Any PASSPHRASE is stored in the Kickstart in plaintext, and the Kickstart must then be protected accordingly. Omitting the `--passphrase=` option from the partition definition will cause the installer to pause and interactively ask for the passphrase during installation. By default, the `Anaconda` installer uses `aes-xts-plain64` cipher with a minimum `512` bit key size which should be compatible with FIPS enabled. Detailed information on encrypting partitions using LUKS or LUKS ciphers can be found on the Oracle Linux 7 Documentation web site: https://docs.oracle.com/en/operating-systems/oracle-linux/7/security/ol7-install-sec.html. | The risk of a system's physical compromise, particularly mobile systems such as laptops, places its data at risk of compromise. Encrypting this data mitigates the risk of its loss if the system is lost.