AlmaLinux OS 9 must prevent files with the setuid and setgid bit set from being executed on the /boot/efi directory.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-269311 | ALMA-09-026200 | SV-269311r1184099_rule | CCI-001764 | medium |
| Description | ||||
| The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | ||||
| STIG | Date | |||
| Cloud Linux AlmaLinux OS 9 Security Technical Implementation Guide | 2026-02-27 | |||
Details
Check Text (C-269311r1184099_chk)
Verify the /boot/efi directory is mounted with the "nosuid" option with the following command:
$ mount | grep '\s/boot/efi\s'
/dev/sda1 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=ascii,shortname=winnt,errors=remount-ro)
If the /boot/efi file system does not have the "nosuid" option set, this is a finding.
Fix Text (F-73243r1048310_fix)
Modify "/etc/fstab" to use the "nosuid" option on the "/boot/efi" directory.