1.1.5 Ensure noexec option set on /tmp partition (Scored)
Profile Applicability
Level 1 - Server Level 1 - Workstation
Description
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
.
Audit
If a /tmp
partition exists run the following command and verify that the noexec
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 noexec
to the /tmp
mount options:
[Mount] Options=mode=1777,strictatime,noexec,nodev,nosuid
Run the following command to remount /tmp
:
# mount -o remount,noexec /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
.