1.1.4 Ensure nosuid option set on /tmp partition

Information

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

Rationale:

Since the /tmp filesystem is only intended for temporary file storage, set this option to ensure that users cannot create setuid files in /tmp.

Solution

Edit /etc/systemd/system/local-fs.target.wants/tmp.mount to add nodev to the /tmp mount options:

[Mount]
Options=mode=1777,strictatime,noexec,nodev,nosuid

Run the following command to remount /tmp :

# mount -o remount,nodev /tmp

Notes:

systemd includes the tmp.mount service which should be used instead of configuring /etc/fstab. Mounting options are configured in the Options setting in /etc/systemd/system/local-fs.target.wants/tmp.mount.

See Also

https://workbench.cisecurity.org/files/2619

Item Details

Category: CONFIGURATION MANAGEMENT

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

Plugin: Unix

Control ID: f8df415c2cc4d390cf1037be5499f5b4df8f5c92ae8455b267186d5802cfc572