FreeBSD : FreeBSD -- Cross-mount links between nullfs(5) mounts (b72bad1c-20ed-11e3-be06-000c29ee3065)

Low Nessus Plugin ID 70263


The remote FreeBSD host is missing one or more security-related updates.


Problem Description :

The nullfs(5) implementation of the VOP_LINK(9) VFS operation does not check whether the source and target of the link are both in the same nullfs instance. It is therefore possible to create a hardlink from a location in one nullfs instance to a file in another, as long as the underlying (source) filesystem is the same.

Impact :

If multiple nullfs views into the same filesystem are mounted in different locations, a user with read access to one of these views and write access to another will be able to create a hard link from the latter to a file in the former, even though they are, from the user's perspective, different filesystems. The user may thereby gain write access to files which are nominally on a read-only filesystem.


Update the affected packages.

See Also

Plugin Details

Severity: Low

ID: 70263

File Name: freebsd_pkg_b72bad1c20ed11e3be06000c29ee3065.nasl

Version: $Revision: 1.4 $

Type: local

Published: 2013/10/02

Modified: 2016/08/10

Dependencies: 12634

Risk Information

Risk Factor: Low


Base Score: 3.7

Temporal Score: 3.2

Vector: CVSS2#AV:L/AC:H/Au:N/C:P/I:P/A:P

Temporal Vector: CVSS2#E:ND/RL:OF/RC:C

Vulnerability Information

CPE: p-cpe:/a:freebsd:freebsd:FreeBSD, cpe:/o:freebsd:freebsd

Required KB Items: Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info, Settings/ParanoidReport

Exploit Available: false

Exploit Ease: No known exploits are available

Patch Publication Date: 2013/09/19

Vulnerability Publication Date: 2013/09/10

Reference Information

CVE: CVE-2013-5710

BID: 62303

OSVDB: 97181

FreeBSD: SA-13:13.nullfs