high8.8
CVE-2025-15547
By default, jailed processes cannot mount filesystems, including nullfs(4).
Impact
By default, jailed processes cannot mount filesystems, including nullfs(4). However, the allow.mount.nullfs option enables mounting nullfs filesystems, subject to privilege checks. If a privileged user within a jail is able to nullfs-mount directories, a limitation of the kernel's path lookup logic allows that user to escape the jail's chroot, yielding access to the full filesystem of the host or parent jail. In a jail configured to allow nullfs(4) mounts from within the jail, the jailed root user can escape the jail's filesystem root.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Freebsd | Freebsd | Versions 13.5, 14.3 |