Blue Coat Systems WinProxy CONNECT Method Heap Overflow Vulnerability

iDefense Security Advisory 02.02.07
http://labs.idefense.com/intelligence/vulnerabilities/
Feb 02, 2007

I. BACKGROUND

BlueCoat WinProxy is an Internet sharing proxy server designed for small to
medium businesses. In addition to internet sharing Winproxy also hosts a
series of security, anti-spam and anti-spyware capabilities. More
information can be located at the link shown below.

http://www.winproxy.com/

II. DESCRIPTION

Remote exploitation of a design error in Blue Coat Systems Inc.'s WinProxy
allows attackers to trigger a heap corruption vulnerability.  

The vulnerability can be triggered by sending an overly long HTTP CONNECT
request to WinProxy's HTTP proxy service.

III. ANALYSIS

Exploitation allows an attacker to cause a denial of service condition or
potentially execute arbitrary code.

Overly long payloads will result in a non-exploitable DoS condition.

IV. DETECTION

iDefense has confirmed this vulnerability in WinProxy 6.1a and 6.0 r1c. All
previous versions are suspected vulnerable.

V. WORKAROUND

Disabling the WinProxy HTTP protocol will prevent this attack.

VI. VENDOR RESPONSE

Blue Coat Systems has addressed this vulnerability within version 6.1r1c of
WinProxy.

VII. CVE INFORMATION

A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.

VIII. DISCLOSURE TIMELINE

08/16/2006  Initial vendor notification
09/19/2006  Initial vendor response
12/06/2006  Second vendor notification
02/02/2007  Coordinated public disclosure

IX. CREDIT

This vulnerability was reported to iDefense by Manuel Santamarina Suarez
aka 'FistFuXXer'.

Get paid for vulnerability research
http://labs.idefense.com/methodology/vulnerability/vcp.php

Free tools, research and upcoming events
http://labs.idefense.com/

X. LEGAL NOTICES

Copyright © 2006 iDefense, Inc.

Permission is granted for the redistribution of this alert electronically.
It may not be edited in any way without the express written consent of
iDefense. If you wish to reprint the whole or any part of this alert in
any other medium other than electronically, please e-mail
customerservice@idefense.com for permission.

Disclaimer: The information in the advisory is believed to be accurate at
the time of publishing based on currently available information. Use of
the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on, this
information.