Information
The operating system must not allow removable media to be used as the boot loader unless approved.
Rationale:
Malicious users with removable boot media can gain access to a system configured to use removable media as the boot loader. If removable media is designed to be used as the boot loader, the requirement must be documented with the Information System Security Officer (ISSO).
NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.
Solution
Remove alternate methods of booting the system from removable media or document the configuration to boot from removable media with the Authorizing Official.
Example: vim /etc/default/grub
Add this in the first menu entry
set root=(hd0,1)
Any changes made to /etc/default/grub require you to run grub2-mkconfig to re-generate the /boot/grub2/grub.cfg file.
Example:
# grub2-mkconfig -o /boot/grub2/grub.cfg
Notes:
This Benchmark recommendation maps to:
Red Hat Enterprise Linux 7 Security Technical Implementation Guide:
Version 2, Release: 3 Benchmark Date: 26 Apr 2019
Vul ID: V-72075
Rule ID: SV-86699r2_rule
STIG ID: RHEL-07-021700
Severity: CAT II