RE: Websense Blocked Sites XSS

["Hubbard, Dan" <dhubbard () websense com>]

All;

We now have a fix available for all platforms of version 5.01 also.
Please update the entry below to include fixes for 5.1 and 5.01. All
Websense customers can receive the fix free of charge through our
technical support department.

Thanks



-----Original Message-----
From: Mr. P.Taylor [mailto:petert () imagine-sw com] 
Sent: Wednesday, December 03, 2003 8:36 AM
To: Hubbard, Dan
Cc: aleph1 () securityfocus com; bugtraq () securityfocus com
Subject: Websense Blocked Sites XSS


Websense Blocked Sites XSS

Risk: High

Product: Websense Enterprise v4.3.0 - v5.1 (Maybe others we only tested
this version)

Product URL: http://www.websense.com

Found By: PeterT - petert () imagine-sw com

Problem:
When Websense blocks a web site, it returns a web page to the browser
stating that the site has been blocked. This error message contains the
URL which was requested. Websense does not do any validation or encoding
of the URL before returning it in the error message. This allows an
attacker to supply a URL that contains script <JavaScript, ActiveX, VB).
This script will run in the context of a server in the trusted domain
and combined with other IE flaws can have serious consequences.

We have marked this as a High risk because we believe that allowing
attackers to run arbitrary programs on your desktop at will, is a
serious problem.


Proof of Concept:
A URL like
http://BlockedSite?<SCRIPT>alert('hello')</SCRIPT> will run script.

Resolution:
The vendor has come out with a patch. Notified on Nov 29, 2003.

Thanks to Websense for fixing this issue.

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for use in an AS IS condition. There are no warranties with regard to
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whatsoever arising out of or in connection with the use or spread of
this information. Any use of this information is at the user's own risk.