-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

                     Symantec Vulnerability Research
                     http://www.symantec.com/research
                           Security Advisory

   Advisory ID: SYMSA-2007-006
Advisory Title: Citrix EPA ActiveX Control Design Flaw
        Author: Michael White / michael_white@symantec.com
  Release Date: 19-07-2007
   Application: Citrix Access Gateway
      Platform: Internet Explorer/Win32
      Severity: Remote arbitrary code execution
 Vendor status: Patch available
    CVE Number: CVE-2007-3679
     Reference: http://www.securityfocus.com/bid/24865


Overview:

Citrix Access Gateway offers a clientless SSL VPN solution
implemented through a series of browser-based controls. As part of
the endpoint validation, the ActiveX control for Internet Explorer
downloads and executes a series of executable modules from the
remote server.

Details:

Researchers identified that the endpoint checking control can be
embedded in any web page and subverted to download and execute any
executable module of the attacker’s choosing.

This vulnerability represents a design flaw in the architecture of
the endpoint validation practice.

A high level of browser trust is required to allow the endpoint
checks to function correctly, and the control is signed by Citrix
Corporation.

Vendor Response:

This has been addressed by a product update.
See http://support.citrix.com/article/CTX113815

Recommendation:

Apply the product update as detailed in 
http://support.citrix.com/article/CTX113815

Common Vulnerabilities and Exposures (CVE) Information:

The Common Vulnerabilities and Exposures (CVE) project has assigned
the following names to these issues.  These are candidates for
inclusion in the CVE list (http://cve.mitre.org), which standardizes
names for security problems.

  CVE-2007-3679

- -------Symantec Vulnerability Research Advisory Information-------

For questions about this advisory, or to report an error:
research@symantec.com

For details on Symantec's Vulnerability Reporting Policy:
http://www.symantec.com/research/Symantec-Responsible-Disclosure.pdf

Symantec Vulnerability Research Advisory Archive:
http://www.symantec.com/research/

Symantec Vulnerability Research GPG Key:
http://www.symantec.com/research/Symantec_Vulnerability_Research_GPG.asc

- -------------Symantec Product Advisory Information-------------

To Report a Security Vulnerability in a Symantec Product:
secure@symantec.com

For general information on Symantec's Product Vulnerability
reporting and response:
http://www.symantec.com/security/

Symantec Product Advisory Archive:
http://www.symantec.com/avcenter/security/SymantecAdvisories.html

Symantec Product Advisory PGP Key:
http://www.symantec.com/security/Symantec-Vulnerability-Management-Key.asc

- ---------------------------------------------------------------

Copyright (c) 2007 by Symantec Corp.
Permission to redistribute this alert electronically is granted
as long as it is not edited in any way unless authorized by
Symantec Consulting Services. Reprinting the whole or part of
this alert in any medium other than electronically requires
permission from research@symantec.com.

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.

Symantec, Symantec products, and Symantec Consulting Services are
registered trademarks of Symantec Corp. and/or affiliated companies
in the United States and other countries. All other registered and
unregistered trademarks represented in this document are the sole
property of their respective companies/owners.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (MingW32)

iD8DBQFGnRXXuk7IIFI45IARAla8AKDKwcYD23htC+trwq1Ke5Qvam99YACfUgJh
VynDvAnppLmojz2wbrLfR+U=
=QakL
-----END PGP SIGNATURE-----