4.1.18 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.

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 line

-e 2

at the end of the file

Notes:

This setting will ensure reloading the auditd config to set active settings requires a system reboot.

See Also

https://workbench.cisecurity.org/files/2688

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, CSCv7|5.1

Plugin: Unix

Control ID: fdc23d0e33e90d17f7c1e3b03626d970edb220f11c412a717221a4aabc39c14e