Ensure nosuid option set on /tmp partition
Profile
Level 1 - Server, Level 1 - Workstation, Assessment: Automated
Description
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.
Audit Procedure
Command Line
- IF - a separate partition exists for
/tmp, verify that the nosuid option is set.
Run the following command to verify that the nosuid mount option is set.
Example:
Nothing should be returned
Expected Result
Nothing should be returned
Remediation
Command Line
- IF - a separate partition exists for
/tmp.
Edit the /etc/fstab file and add nosuid to the fourth field (mounting options) for the /tmp partition.
Example:
<device> /tmp <fstype> defaults,rw,nosuid,nodev,noexec,relatime 0 0
Run the following command to remount /tmp with the configured options:
Default Value
Not configured by default.
References
- See the fstab(5) manual page for more information.
- NIST SP 800-53 Rev. 5: AC-3, MP-2
- RHEL 8 STIG Vul ID: V-230512
- RHEL 8 STIG Rule ID: SV-230512r854053
CIS Controls
v8 - 3.3 Configure Data Access Control Lists (IG 1, IG 2, IG 3)
v7 - 14.6 Protect Information through Access Control Lists (IG 1, IG 2, IG 3)
MITRE ATT&CK Mappings: T1548, T1548.001 | TA0005 | M1022