Vulnerability Discussion

If auditing is enabled late in the start-up process, the actions of some start-up processes may not be audited. Some audit systems also maintain state information only available if auditing is enabled before a given process is created.

Check

Verify that the Ubuntu operating system enables auditing at system startup.

Verify that the auditing is enabled in grub with the following command:

$ sudo grep "^\s*linux" /boot/grub/grub.cfg

linux /boot/vmlinuz-5.4.0-31-generic root=UUID=74d13bcd-6ebd-4493-b5d2-3ebc37d01702 ro audit=1
linux /boot/vmlinuz-5.4.0-31-generic root=UUID=74d13bcd-6ebd-4493-b5d2-3ebc37d01702 ro recovery nomodeset audit=1

If any linux lines do not contain "audit=1", this is a finding.

Fix

Configure the Ubuntu operating system to produce audit records at system startup.

Edit the "/etc/default/grub" file and add "audit=1" to the "GRUB_CMDLINE_LINUX" option.

To update the grub config file, run:

$ sudo update-grub