The graphical display manager must not be installed on TOSS unless approved.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-253103	TOSS-04-040610	SV-253103r824981_rule		Medium

Description
Internet services that are not required for system or application processes must not be active to decrease the attack surface of the system. Graphical display managers have a long history of security vulnerabilities and must not be used, unless approved and documented.

STIG	Date
Tri-Lab Operating System Stack (TOSS) 4 Security Technical Implementation Guide	2022-08-29

Details

Check Text ( C-56556r824979_chk )
Verify that the system is configured to boot to the command line: $ systemctl get-default multi-user.target If the system default target is not set to "multi-user.target" and the Information System Security Officer (ISSO) lacks a documented requirement for a graphical user interface, this is a finding. Verify that a graphical user interface is not installed: $ rpm -qa \| grep xorg \| grep server Ask the System Administrator if use of a graphical user interface is an operational requirement. If the use of a graphical user interface on the system is not documented with the ISSO, this is a finding.

Check Text ( C-56556r824979_chk )

Verify that the system is configured to boot to the command line:

$ systemctl get-default
multi-user.target

If the system default target is not set to "multi-user.target" and the Information System Security Officer (ISSO) lacks a documented requirement for a graphical user interface, this is a finding.

Verify that a graphical user interface is not installed:

$ rpm -qa | grep xorg | grep server

Ask the System Administrator if use of a graphical user interface is an operational requirement.

If the use of a graphical user interface on the system is not documented with the ISSO, this is a finding.

Fix Text (F-56506r824980_fix)
Document the requirement for a graphical user interface with the ISSO or reinstall the operating system without the graphical user interface. If reinstallation is not feasible, then continue with the following procedure: Open an SSH session and enter the following commands: $ sudo systemctl set-default multi-user.target $ sudo yum remove xorg-x11-server-Xorg xorg-x11-server-common xorg-x11-server-utils xorg-x11-server-Xwayland A reboot is required for the changes to take effect.

Fix Text (F-56506r824980_fix)

Document the requirement for a graphical user interface with the ISSO or reinstall the operating system without the graphical user interface. If reinstallation is not feasible, then continue with the following procedure:

Open an SSH session and enter the following commands:

$ sudo systemctl set-default multi-user.target

$ sudo yum remove xorg-x11-server-Xorg xorg-x11-server-common xorg-x11-server-utils xorg-x11-server-Xwayland

A reboot is required for the changes to take effect.