AlmaLinux OS 9 must prevent files with the setuid and setgid bit set from being executed on the /boot directory.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-269313	ALMA-09-026420	SV-269313r1050195_rule		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
CloudLinux AlmaLinux OS 9 Security Technical Implementation Guide	2025-05-22

Details

Check Text (C-73344r1048315_chk)

Verify the /boot directory is mounted with the "nosuid" option with the following command:

$ mount | grep '\s/boot\s'

/dev/sda2 on /boot type xfs (rw,nosuid,nodev,noexec,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota)

If the /boot file system does not have the "nosuid" option set, this is a finding.

Fix Text (F-73245r1048316_fix)

Modify "/etc/fstab" to use the "nosuid" option on the "/boot" directory.