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

2006-08-0800:00:00

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Gentoo Linux Security Advisory GLSA 200608-12

                                        http://security.gentoo.org/

Severity: High
Title: x11vnc: Authentication bypass in included LibVNCServer code
Date: August 07, 2006
Bugs: #142559
ID: 200608-12

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 &quot;&gt;=x11-misc/x11vnc-0.8.1&quot;

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
[email protected] or alternatively, you may file a bug at
http://bugs.gentoo.org.