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V-282470

CAT I (High)

TOSS 5 must require a unique superuser name upon booting into single-user and maintenance modes.

Rule ID

SV-282470r1201601_rule

STIG

Tri-Lab Operating System Stack (TOSS) 5 Security Technical Implementation Guide

Version

V1R1

CCIs

CCI-000213

Discussion

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

Check Content

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

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