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LTSP: Authentication bypass in included LibVNCServer code


1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 200703-19 / ltsp
Release Date March 18, 2007
Latest Revision March 18, 2007: 01
Impact high
Exploitable remote
Package Vulnerable versions Unaffected versions Architecture(s)
net-misc/ltsp < 4.2-r1 >= 4.2-r1 All supported architectures

Related bugreports: #142661


LTSP includes a version of libVNCServer that is vulnerable to an authentication bypass.

2.  Impact Information


The Linux Terminal Server Project adds thin-client support to Linux servers.


The LTSP server 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). The LTSP VNC server will accept this security type, even if it is not offered by the server.


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

3.  Resolution Information


There is no known workaround at this time.


All LTSP users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=net-misc/ltsp-4.2-r1"

4.  References


Page updated March 18, 2007

Summary: This is a Gentoo Linux Security Advisory

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