4.1.3.41 Ensure the audit configuration is immutable

Information

Set system audit so that audit rules cannot be modified with auditctl . Setting the flag '-e 2' forces audit to be put in immutable mode. Audit changes can only be made on system reboot.

Note: This setting will require the system to be rebooted to update the active auditd configuration settings.

Rationale:

In immutable mode, unauthorized users cannot execute changes to the audit system to potentially hide malicious activity and then put the audit rules back. Users would most likely notice a system reboot and that could alert administrators of an attempt to make unauthorized audit changes.

Solution

Edit or create the file /etc/audit/rules.d/99-finalize.rules and add the following line at the end of the file:

-e 2

See Also

https://workbench.cisecurity.org/files/3636