[ GLSA 200608-12 ] x11vnc: Authentication bypass in included LibVNCServer code

[Sune Kloppenborg Jeppesen <jaervosz () gentoo org>]

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Gentoo Linux Security Advisory                           GLSA 200608-12
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                                            http://security.gentoo.org/
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  Severity: High
     Title: x11vnc: Authentication bypass in included LibVNCServer code
      Date: August 07, 2006
      Bugs: #142559
        ID: 200608-12

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Synopsis
========

VNC servers created with x11vnc accept insecure protocol types, even
when the server does not offer it, resulting in the possibility of
unauthorized access to the server.

Background
==========

x11vnc provides VNC servers for X displays.

Affected packages
=================

    -------------------------------------------------------------------
     Package          /  Vulnerable  /                      Unaffected
    -------------------------------------------------------------------
  1  x11-misc/x11vnc       < 0.8.1                            >= 0.8.1

Description
===========

x11vnc includes vulnerable LibVNCServer code, which fails to properly
validate protocol types effectively letting users decide what protocol
to use, such as "Type 1 - None" (GLSA-200608-05). x11vnc will accept
this security type, even if it is not offered by the server.

Impact
======

An attacker could exploit this vulnerability to gain unauthorized
access with the privileges of the user running the VNC server.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All x11vnc users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=x11-misc/x11vnc-0.8.1"

References
==========

  [ 1 ] CVE-2006-2450
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-2450
  [ 2 ] GLSA-200608-05
        http://www.gentoo.org/security/en/glsa/glsa-200608-05.xml

Availability
============

This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

  http://security.gentoo.org/glsa/glsa-200608-12.xml

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users machines is of utmost
importance to us. Any security concerns should be addressed to
security () gentoo org or alternatively, you may file a bug at
http://bugs.gentoo.org.

License
=======

Copyright 2006 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

http://creativecommons.org/licenses/by-sa/2.5

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