RHEL 9 must mount /dev/shm with the noexec option.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-257864	RHEL-09-231115	SV-257864r925579_rule		Medium

Description
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.

STIG	Date
Red Hat Enterprise Linux 9 Security Technical Implementation Guide	2023-12-01

Details

Check Text ( C-61605r925577_chk )
Verify "/dev/shm" is mounted with the "noexec" option with the following command: $ mount | grep /dev/shm tmpfs on /dev/shm type tmpfs (rw,nodev,nosuid,noexec,seclabel) If the /dev/shm file system is mounted without the "noexec" option, this is a finding.

Fix Text (F-61529r925578_fix)
Modify "/etc/fstab" to use the "noexec" option on the "/dev/shm" file system.