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.
Attack Parameters
Attack Vector
Local
Requires local access
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products 17
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:13.5:-:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:13.5:p1:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:13.5:p2:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:13.5:p3:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:13.5:p4:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:13.5:p5:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:13.5:p6:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:13.5:p7:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:13.5:p8:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:14.3:-:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:14.3:p1:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:14.3:p2:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:14.3:p3:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:14.3:p4:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:14.3:p5:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:14.3:p6:*:*:*:*:*:*
|
— | — |
|
Freebsd Freebsd
cpe:2.3:o:freebsd:freebsd:14.3:p7:*:*:*:*:*:*
|
— | — |