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. In the graphical environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.

Check

Verify the operating system is not configured to reboot the system when Ctrl-Alt-Delete is pressed.

Check that the ctrl-alt-del.target is masked and not active with the following command:

# systemctl status ctrl-alt-del.target

ctrl-alt-del.target
Loaded: masked (/dev/null; bad)
Active: inactive (dead)

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

If the ctrl-alt-del.target is active, this is a finding.

Fix

Configure the system to disable the Ctrl-Alt-Delete sequence for the command line with the following commands:

$ sudo systemctl disable ctrl-alt-del.target

$ sudo systemctl mask ctrl-alt-del.target