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V-252938

CAT I (High)

The systemd Ctrl-Alt-Delete burst key sequence in TOSS must be disabled.

Rule ID

SV-252938r1155810_rule

STIG

Tri-Lab Operating System Stack (TOSS) 4 Security Technical Implementation Guide

Version

V2R5

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. In a graphical user 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 Content

Verify TOSS is configured to not reboot the system when Ctrl-Alt-Delete is pressed seven times within two seconds with the following command:

$ sudo grep -iR CtrlAltDelBurstAction /etc/systemd/system*
/etc/systemd/system.conf.d/55-CtrlAltDel-BurstAction:CtrlAltDelBurstAction=none

If the "CtrlAltDelBurstAction" is not set to "none", commented out, or is missing, this is a finding.

Fix Text

Configure TOSS to disable the CtrlAltDelBurstAction by adding it to a drop file in a "/etc/systemd/system.conf.d/" configuration file:

If no drop file exists, create one with the following command:

$ sudo mkdir -p /etc/systemd/system.conf.d && sudo vi /etc/systemd/system.conf.d/55-CtrlAltDel-BurstAction

Edit the file to contain the setting by adding the following text:

CtrlAltDelBurstAction=none

Reload the daemon for this change to take effect.

$ sudo systemctl daemon-reload