1.1.16 Ensure nosuid option set on /dev/shm partition

Information

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.

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,nosuid /dev/shm

Notes:

The setting in /etc/default/rcS, if present, will still be used, but the setting in /etc/default/tmpfs will take precedence if enabled. If desired, the defaults may also be overridden with an entry in in /etc/fstab

/run/shm was previously /dev/shm, and a compatibility symlink or bind mount will be created to allow the old path to continue to function. If an fstab entry for /dev/shm exists instead of /run/shm, then /dev/shm will continue to be used.

See Also

https://workbench.cisecurity.org/files/2658

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, CSCv7|5.1

Plugin: Unix

Control ID: aa136e0affb355f135e890270ad00b91afb630cabdd3abf8be1fa9337146015b