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

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-257837	SRG-OS-000480-GPOS-00227	RHEL-09-215070	SV-257837r1044910_rule	2025-02-27	2

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.

ℹ️ Check
Verify that a graphical user interface is not installed with the following command: $ dnf list --installed "xorg-x11-server-common" Error: No matching Packages to list If the "xorg-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
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

✔️ 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