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V-271451

CAT I (High)

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

Rule ID

SV-271451r1137691_rule

STIG

Oracle Linux 9 Security Technical Implementation Guide

Version

V1R5

CCIs

CCI-000213

Discussion

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

Check Content

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 Text

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'