OpenSSH X11UseLocalhost X11 Forwarding Port Hijacking

Low Nessus Plugin ID 44080


The remote SSH service may be affected by an X11 forwarding port hijacking vulnerability.


According to its banner, the version of SSH installed on the remote host is older than 5.1 and may allow a local user to hijack the X11 forwarding port. The application improperly sets the 'SO_REUSEADDR' socket option when the 'X11UseLocalhost' configuration option is disabled.

Note that most operating systems, when attempting to bind to a port that has previously been bound with the 'SO_REUSEADDR' option, will check that either the effective user-id matches the previous bind (common BSD-derived systems) or that the bind addresses do not overlap (Linux and Solaris). This is not the case with other operating systems such as HP-UX.


Upgrade to OpenSSH version 5.1 or later.

See Also

Plugin Details

Severity: Low

ID: 44080

File Name: openssh_51.nasl

Version: $Revision: 1.4 $

Type: remote

Family: Misc.

Published: 2011/10/04

Modified: 2016/05/12

Dependencies: 10267

Risk Information

Risk Factor: Low


Base Score: 1.2

Temporal Score: 1

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

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

Vulnerability Information

CPE: cpe:/a:openbsd:openssh

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2008/07/21

Vulnerability Publication Date: 2008/07/21

Reference Information

CVE: CVE-2008-3259

BID: 30339

OSVDB: 47227

CWE: 200