1.1.16 Ensure nosuid option set on /dev/shm partition (Scored)
Profile Applicability
Level 1 - Server Level 1 - Workstation
Description
The nosuid
mount option specifies that the filesystem cannot contain setuid
files.
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.
Audit
Run the following command and verify that the nosuid
option is set on /dev/shm
.
# mount | grep /dev/shm tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,noexec,relatime)
Remediation
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,nosuid /dev/shm
Notes
/dev/shm
is not specified in /etc/fstab
despite being mounted by default. The following line will implement the recommended /dev/shm
mount options in /etc/fstab
:
tmpfs /dev/shm tmpfs defaults,nodev,nosuid,noexec 0 0