OL 9 must be configured so that the graphical display manager is not the default target unless approved.

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.

Verify that OL 9 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.

Configure OL 9 to boot to the command line.

Set the default target to multi-user with the following command: $ sudo systemctl set-default multi-user.target

If there is an operational requirement for a graphical user interface, document it with the ISSO.