A graphical display manager must not be installed on RHEL 9 unless approved.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-257837	RHEL-09-215070	SV-257837r925498_rule		Medium

Description
Unnecessary service packages must not be installed 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
Red Hat Enterprise Linux 9 Security Technical Implementation Guide	2023-12-01

Details

Check Text ( C-61578r925496_chk )
Verify that a graphical user interface is not installed with the following command: $ sudo dnf list --installed "xorg*common" Error: No matching Packages to list If the "x11-server-common" package is installed, and the use of a graphical user interface has not been documented with the information system security officer (ISSO) as an operational requirement, this is a finding.

Fix Text (F-61502r925497_fix)

Document the requirement for a graphical user interface with the ISSO or remove all xorg packages with the following command: Warning: If you are accessing the system through the graphical user interface, change to the multi-user.target with the following command: $ sudo systemctl isolate multi-user.target Warning: Removal of the graphical user interface will immediately render it useless. The following commands must not be run from a virtual terminal emulator in the graphical interface. $ sudo dnf remove "xorg*" $ sudo systemctl set-default multi-user.target