RHEL 9 must prevent a user from overriding the Ctrl-Alt-Del sequence settings for the graphical user interface.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-258032	RHEL-09-271110	SV-258032r991589_rule		Medium

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

STIG	Date
Red Hat Enterprise Linux 9 Security Technical Implementation Guide	2024-06-04

Details

Check Text ( C-61773r926081_chk )
Verify that users cannot enable the Ctrl-Alt-Del sequence in the GNOME desktop with the following command: Note: This requirement assumes the use of the RHEL 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. $ grep logout /etc/dconf/db/local.d/locks/* /org/gnome/settings-daemon/plugins/media-keys/logout If the output is not "/org/gnome/settings-daemon/plugins/media-keys/logout", the line is commented out, or the line is missing, this is a finding.

Check Text ( C-61773r926081_chk )

Verify that users cannot enable the Ctrl-Alt-Del sequence in the GNOME desktop with the following command:

Note: This requirement assumes the use of the RHEL 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable.

$ grep logout /etc/dconf/db/local.d/locks/*

/org/gnome/settings-daemon/plugins/media-keys/logout

If the output is not "/org/gnome/settings-daemon/plugins/media-keys/logout", the line is commented out, or the line is missing, this is a finding.

Fix Text (F-61697r926082_fix)
Configure RHEL 9 to disallow the user changing the Ctrl-Alt-Del sequence in the GNOME desktop. Create a database to container system-wide graphical user logon settings (if it does not already exist) with the following command: $ sudo touch /etc/dconf/db/local.d/locks/session Add the following line to the session locks file to prevent nonprivileged users from modifying the Ctrl-Alt-Del setting: /org/gnome/settings-daemon/plugins/media-keys/logout Run the following command to update the database: $ sudo dconf update

Fix Text (F-61697r926082_fix)

Configure RHEL 9 to disallow the user changing the Ctrl-Alt-Del sequence in the GNOME desktop.

Create a database to container system-wide graphical user logon settings (if it does not already exist) with the following command:

$ sudo touch /etc/dconf/db/local.d/locks/session

Add the following line to the session locks file to prevent nonprivileged users from modifying the Ctrl-Alt-Del setting:

/org/gnome/settings-daemon/plugins/media-keys/logout

Run the following command to update the database:

$ sudo dconf update