OL 9 must require a unique superuser's name upon booting into single-user and maintenance modes.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
high	V-271451	SRG-OS-000080-GPOS-00048	OL09-00-000050	SV-271451r1091065_rule	2025-05-08	1

Description
Having a nondefault grub superuser username makes password-guessing attacks less effective.

ℹ️ Check
Verify that OL 9 requires a unique username for the grub superuser account. Verify the boot loader superuser account has been set with the following command: $ sudo grep -A1 "superusers" /etc/grub2.cfg set superusers="<superusers-account>" export superusers password_pbkdf2 root ${GRUB2_PASSWORD} The <superusers-account> is the actual account name different from common names like root, admin, or administrator. If superusers contains easily guessable usernames, this is a finding.

ℹ️ Check

Verify that OL 9 requires a unique username for the grub superuser account. Verify the boot loader superuser account has been set with the following command: $ sudo grep -A1 "superusers" /etc/grub2.cfg set superusers="<superusers-account>" export superusers password_pbkdf2 root ${GRUB2_PASSWORD} The <superusers-account> is the actual account name different from common names like root, admin, or administrator. If superusers contains easily guessable usernames, this is a finding.

✔️ Fix
Configure OL 9 to have a unique username for the grub superuser account. Edit the "/etc/grub.d/01_users" file and add or modify the following lines in the "### BEGIN /etc/grub.d/01_users ###" section: set superusers="superusers-account" export superusers Once the superuser account has been added, update the grub.cfg file by running: $ sudo grubby --update-kernel=ALL'