Amazon Linux 2023 must mount /dev/shm with the nodev option.

STIG ID: AZLX-23-002585  |  SRG: SRG-OS-000368-GPOS-00154 |  Severity: medium (CAT II)  |  CCI: CCI-001764 |  Vulnerability Id: V-274179

Vulnerability Discussion

The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.

Check

Verify Amazon Linux 2023 is configured so that "/dev/shm" is mounted with the "nodev" 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 "nodev" option, this is a finding.

Fix

Configure Amazon Linux 2023 so that "/dev/shm" is mounted with the "nodev" option.

Modify "/etc/fstab" to use the "nodev" option on the "/dev/shm" file system.