Blue Coat Systems WinProxy Host Header Stack Overflow Vulnerability
iDefense Security Advisory 01.05.06
January 05, 2006
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 from the vendors site at:
Remote exploitation of a buffer overflow vulnerability in Blue Coat
Systems Inc.'s WinProxy allows for the remote execution of arbitrary
code by attackers.
The vulnerability can be triggered by sending an overly long Host:
string to the web proxy service.
Exploitation of this vulnerability is trivial. An overly long header
directly overwrites the SEH handler for the frame allowing for control
iDefense has confirmed this vulnerability in WinProxy 6.0. All previous
versions are suspected to be vulnerable.
Disabling the WinProxy web proxy protocol will prevent this attack.
VI. VENDOR RESPONSE
Blue Coat has released WinProxy 6.1a to address this vulnerability.
VII. CVE INFORMATION
The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2005-4085 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org), which standardizes names for
VIII. DISCLOSURE TIMELINE
12/07/2005 Initial vendor notification
12/08/2005 Initial vendor response
01/05/2006 Coordinated public disclosure
This vulnerability was discovered by FistFuXXer.
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X. LEGAL NOTICES
Copyright =A9 2006 iDefense, Inc.
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