RHEL 9 must mount /tmp with the nosuid option.

Documentable No

Rule ID SV-257868r958804_rule

CCI References

CCI-001764

Discussion

The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.

Check Procedure

Verify "/tmp" is mounted with the "nosuid" option:

$ mount | grep /tmp

/dev/mapper/rhel-tmp on /tmp type xfs (rw,nodev,nosuid,noexec,seclabel)

If the "/tmp" file system is mounted without the "nosuid" option, this is a finding.

Fix Action

Modify "/etc/fstab" to use the "nosuid" option on the "/tmp" directory.