LTSP: Authentication bypass in included LibVNCServer code

Background

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

Description

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.

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 LTSP users should upgrade to the latest version:

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