1.1.9 Ensure nosuid option set on /dev/shm partition

Information

The nosuid mount option specifies that the filesystem cannot contain setuid files.



Note: /dev/shm is mounted automatically by systemd. /dev/shm needs to be added to /etc/fstab to add mount options even though it is already being mounted on boot.

Rationale:

Setting this option on a file system prevents users from introducing privileged programs onto the system and allowing non-root users to execute them.

Solution

Edit the /etc/fstab file and add nosuid to the fourth field (mounting options) for the /dev/shm partition. See the fstab(5) manual page for more information.


Run the following command to remount /dev/shm:

# mount -o remount,noexec,nodev,nosuid /dev/shm

See Also

https://workbench.cisecurity.org/files/3682