8e6 Technologies R3000 Internet Filter Bypass with Host Decoy

From: <nnposter_at_disclosed.not>
Date: Tue, 5 Aug 2008 01:19:46 -0600

('binary' encoding is not supported, stored as-is) 8e6 Technologies R3000 Internet Filter Bypass with Host Decoy

Product:

8e6 Technologies R3000 Internet Filter
http://www.8e6.com/network-security/internet-filtering/internet-filtering.html

The HTTP URL filtering function provided by the 8e6 Technologies R3000 Internet Filter contains a vulnerability in that it can mistake a properly formed custom header for the Host header. This can be exploited for bypassing the filter by providing an allowed site in the custom header.

Examples:

  GET / HTTP/1.0
  X-DecoyHost: www.allowed.org
  Host: www.blocked.org

  GET / HTTP/1.0
  X-Decoy: Host: www.allowed.org
  Host: www.blocked.org

This weakness cannot be leveraged for circumventing blocks based on IP addresses (as opposed to DNS names).

The vulnerability has been identified in version 2.0.12.10. However, other versions may be also affected.

Solution:
None

Found by:
nnposter
Received on Aug 05 2008