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

http://security.gentoo.org/

Severity:	high
Title:	x11vnc: Authentication bypass in included LibVNCServer code
Date:	08/07/2006
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	Architecture(s)
x11-misc/x11vnc	< 0.8.1	>= 0.8.1	All supported architectures

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

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 https://bugs.gentoo.org.