1.1.3 Ensure nodev option set on /tmp partition (Scored)
Profile Applicability
Level 1 - Server Level 1 - Workstation
Description
The nodev mount option specifies that the filesystem cannot contain special devices.
Rationale
Since the /tmp filesystem is not intended to support devices, set this option to ensure that users cannot attempt to create block or character special devices in /tmp.
Audit
If a /tmp partition exists run the following command and verify that the nodev option is set on /tmp:
# mount | grep /tmp tmpfs on /tmp type tmpfs (rw,nosuid,nodev,noexec,relatime)
Remediation
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] # 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/tmp.mount.