Vulnerability Discussion

A locally logged-on user who presses Ctrl-Alt-Delete, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.

Check

Verify Ubuntu 22.04 LTS is not configured to reboot the system when Ctrl-Alt-Delete is pressed by using the following command:

$ systemctl status ctrl-alt-del.target
ctrl-alt-del.target
Loaded: masked (Reason: Unit ctrl-alt-del.target is masked.)
Active: inactive (dead)

If the "ctrl-alt-del.target" is not masked, this is a finding.

Fix

Configure Ubuntu 22.04 LTS to disable the Ctrl-Alt-Delete sequence for the command line by using the following commands:

$ sudo systemctl disable ctrl-alt-del.target

$ sudo systemctl mask ctrl-alt-del.target

Reload the daemon to take effect:

$ sudo systemctl daemon-reload