Vulnerability Discussion

Without verification, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters.

This requirement applies to Ubuntu 24.04 LTS performing security function verification/testing and/or systems and environments that require this functionality.

Check

Note: If AIDE is not installed, this finding is not applicable.

Verify Advanced Intrusion Detection Environment (AIDE) is configured on the system by preforming a manual check:

$ sudo aide -c /etc/aide/aide.conf --check

Example output:
...
Start timestamp: 2024-10-30 14:22:38 -0400 (AIDE 0.18.6)
AIDE found differences between database and filesystem!!
...

If AIDE is being used for system file integrity checking and the command fails, this is a finding.

Fix

Initialize the AIDE package (this may take a few minutes):
$ sudo aideinit
Running aide --init...

The new database will need to be renamed to be read by AIDE:
$ sudo cp -p /var/lib/aide/aide.db.new /var/lib/aide/aide.db

Perform a manual check:
$ sudo aide -c /etc/aide/aide.conf --check

Example output:
...
Start timestamp: 2024-10-30 14:22:38 -0400 (AIDE 0.18.6)
AIDE found differences between database and filesystem!!
...

Done.