Vulnerability Discussion
If auditing is enabled late in the startup process, the actions of some startup 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 the Ubuntu operating system enables auditing at system startup.
Check that the auditing is enabled in grub with the following command:
grep "^\s*linux" /boot/grub/grub.cfg
linux /vmlinuz-4.15.0-55-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash $vt_handoff audit=1
linux /vmlinuz-4.15.0-55-generic root=/dev/mapper/ubuntu--vg-root 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 /etc/default/grub file and add "audit=1" to the GRUB_CMDLINE_LINUX option.
To update the grub config file run,
sudo update-grub