1.1.3 Ensure noexec option set on /tmp partition

Information

The noexec mount option specifies that the filesystem cannot contain executable binaries.

Rationale:

Since the /tmp filesystem is only intended for temporary file storage, set this option to ensure that users cannot run executable binaries from /tmp.

Solution

Edit the /etc/fstab file OR the /etc/systemd/system/local-fs.target.wants/tmp.mount file:
IF /etc/fstab is used to mount /tmp
Edit the /etc/fstab file and add noexec 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,noexec /tmp

OR if systemd is used to mount /tmp:_
Edit /etc/systemd/system/local-fs.target.wants/tmp.mount to add noexec to the /tmp mount options:

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

Run the following command to restart the systemd daemon:

# systemctl daemon-reload

Run the following command to restart tmp.mount

# systemctl restart tmp.mount

See Also

https://workbench.cisecurity.org/files/3490

Item Details

Category: CONFIGURATION MANAGEMENT, SYSTEM AND SERVICES ACQUISITION

References: 800-53|CM-1, 800-53|CM-2, 800-53|CM-6, 800-53|CM-7, 800-53|CM-7(1), 800-53|CM-9, 800-53|SA-3, 800-53|SA-8, 800-53|SA-10, CSCv7|2.6

Plugin: Unix

Control ID: 6ebd18195d2ef35b622d6bac81089a0ad94280884874d78f501fc99de4a81e17