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
If using the /etc/fstab for configuring /tmp do the following:
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
If using systemd tmp.mount for configuring /tmp do the following:
Edit /etc/systemd/system/local-fs.target.wants/tmp.mount and add the nosuid option to the Options line
Example:
[Mount]
What=tmpfs
Where=/tmp
Type=tmpfs
Options=mode=1777,strictatime,noexec,nodev,nosuid
Run the following command to remount /tmp:
# mount -o remount,nosuid /tmp
Additional Information:
If the /etc/fstab includes /tmp it will take precedence over the tmp.mount file
Item Details
Category: CONFIGURATION MANAGEMENT, SYSTEM AND SERVICES ACQUISITION
References: 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, CSCv6|13, CSCv7|5.1
Control ID: 9ff9321662b81c5389fe3115ab664d4c197bff0209cfc1d858e630e19d12a2cf