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V-270712

CAT I (High)

Ubuntu 24.04 LTS must disable the x86 Ctrl-Alt-Delete key sequence.

Rule ID

SV-270712r1068363_rule

STIG

Canonical Ubuntu 24.04 LTS Security Technical Implementation Guide

Version

V1R5

CCIs

CCI-000366

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 Content

Verify Ubuntu 24.04 LTS is not configured to reboot the system when Ctrl-Alt-Delete is pressed with the following command:

$ systemctl status ctrl-alt-del.target
o   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 Text

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
Created symlink /etc/systemd/system/ctrl-alt-del.target ? /dev/null.

Reload the daemon to take effect: 

$ sudo systemctl daemon-reload