[NEWS] Websense Policy Filtering Bypass (User-Agent)

The following security advisory is sent to the securiteam mailing list, and can be found at the SecuriTeam web site: http://www.securiteam.com
- - promotion

The SecuriTeam alerts list - Free, Accurate, Independent.

Get your security news from a reliable source.
http://www.securiteam.com/mailinglist.html

- - - - - - - - -

Websense Policy Filtering Bypass (User-Agent)
------------------------------------------------------------------------

SUMMARY

By spoofing the User-Agent header it is possible to bypass filtering and,
to a lesser extent, monitoring in a Websense Enterprise.

DETAILS

Vulnerable Systems:
* Websense Enterprise version 6.3.1

The following was tested in an unpatched 6.3.1 system using the ISA Server
integration product. It is assumed it will work with other integration
products but this has not been tested. Other User Agents may also work.

I. Install FireFox 2.0.x
II. Obtain and install the User Agent Switcher browser plug-in by Chris
Pederick
III. Add the following User Agents to the plug-in

Description: RealPlayer
User Agent : RealPlayer G2

Description: MSN Messenger
User Agent : MSMSGS

Description: WebEx
User Agent : StoneHttpAgent

IV. Change FireFox's User Agent to any one of the preceding values
V. Browse to a filtered Web site
VI. Content is allowed

Content browsed via this method will be recorded in the Websense database
as being in the "Non-HTTP" category.

Solution:
Websense has corrected the issue in database update 92938 as explained in
article: <http://www.websense.com/SupportPortal/SupportKbs/976.aspx> How
can I ensure that Websense Enterprise filters "all" requests (URL requests
and tunneled protocol requests)?

ADDITIONAL INFORMATION

The information has been provided by <mailto:dink@mrhinkydink.com> Mr.
HinkyDink.
The original article can be found at:
<http://mrhinkydink.blogspot.com/2007/12/websense-policy-filtering-bypass.html> http://mrhinkydink.blogspot.com/2007/12/websense-policy-filtering-bypass.html

========================================

This bulletin is sent to members of the SecuriTeam mailing list.
To unsubscribe from the list, send mail with an empty subject line and body to: list-unsubscribe@securiteam.com
In order to subscribe to the mailing list, simply forward this email to: list-subscribe@securiteam.com

====================
====================

DISCLAIMER:
The information in this bulletin is provided "AS IS" without warranty of any kind.
In no event shall we be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages.