TOSS 5 must require a unique superuser name upon booting into single-user and maintenance modes.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-282470 | TOSS-05-000094 | SV-282470r1201601_rule | CCI-000213 | high |
| Description | ||||
| Having a nondefault grub superuser username makes password-guessing attacks less effective. | ||||
| STIG | Date | |||
| Tri-Lab Operating System Stack (TOSS) 5 Security Technical Implementation Guide | 2026-04-01 | |||
Details
Check Text (C-282470r1201601_chk)
Verify the boot loader superuser account has been set using the following command:
$ sudo grep -A1 "superusers" /etc/grub2.cfg
set superusers="<superusers-account>"
export superusers
The <superusers-account> is the actual account name, which is different from common names like "root", "admin", or "administrator".
If superusers contains easily guessable usernames, this is a finding.
Fix Text (F-86936r1200389_fix)
Configure TOSS 5 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 using the following command:
$ sudo grubby --update-kernel=ALL