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 the /etc/fstab file and add nosuid to the fourth field (mounting options) for the /tmp partition. See the fstab(5) manual page for more information.
Run the following command to remount /tmp :

# mount -o remount,nosuid /tmp

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

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

Run the following command to remount /tmp :

# mount -o remount,nosuid /tmp

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: 3fd7262b2ce0adf2052de771d138be05091585a45a2bf646deafd0c3395f66d9