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



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

   Advisory ID: SYMSA-2007-012
Advisory Title: Microsoft Windows CE IGMP Denial of Service
        Author: Ollie Whitehouse / ollie_whitehouse@symantec.com
  Release Date: 22-10-2007
   Application: Windows CE 5.01 / Windows Mobile 5
      Platform: Microsoft Windows
      Severity: Denial of Service
 Vendor status: Update Available
    CVE Number: CVE-2006-0021
     Reference: http://www.securityfocus.com/bid/16645


Overview:

  This issue was originally discovered by Douglas Nascimento of
  Datacom and published in Microsoft security bulletin MS06-007 on
  Feburary 14th 2006 and subsequently updated March 17th 2006. A
  condition exists with the Microsoft IP stack wherein a specially
  crafted IGMP packet causes a denial of service condition. In
  Microsoft's original advisory, Windows CE was omitted as a
  vulnerable platform; however, In Symantec's testing it was
  discovered that Windows CE 5.01 (shipped as part of the Windows
  Mobile 5 PocketPC and SmartPhone editions) is vulnerable. Symantec
  notified Microsoft in Feburary 2006 of the fact that CE was
  affected with Microsoft releasing a patch in KB930642 in
  Feburary 2007.


Details:

  On the day of release Symantec developed a working trigger for this
  vulnerability. A public exploit for this issue was released by
  Alexey Sintsov on the 21st of March 2006. When an IGMP packet is
  supplied with invalid IP options then it will cause a denial of
  service condition. As IGMP can be sent both via unicast and mulicast
  it is possible to cause the issue to manifest itself in many devices
  with a single packet if appropiate network filtering is not in place.


Vendor Response:

  There is a security vulnerability that could allow for Denial of
  Service (DoS) by sending a specifically crafted TCP/IP packet to the
  mobile device. However most attempts to exploit this vulnerability
  would result in a Denial of Service Condition on the networking
  capabilities of the device.
  
  The following devices may be vulnerable to this issue:
  
  Windows CE 4.2 - Windows CE .NET 4.2 Platform Builder
      Monthly Update (September 2007)
  Windows Mobile 5.0 - A fix for this issue has been provided by
      Microsoft via  http://support.microsoft.com/kb/930642
  Fixed in Windows Mobile 6.0.


Recommendation:

  Windows Mobile 5.0 customers please see your handset manufacturer to
  obtain the update customized for your device to Windows Mobile 6.

  OEMs which utilise Windows CE should ensure KB930642 is applied to
  their build environment. Details can be found here on Microsoft's
  support site - http://support.microsoft.com/kb/930642/.

  Carriers should ensure appropiate network filtering is in place in
  order to protect affected handsets.


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-2006-0021

- -------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)

iD8DBQFHHUm2uk7IIFI45IARAusBAJ9C0DNcJwYpQgwriJ7kMeK7mHPGEACfUS6G
z6cX6HZtfiCvZQx9KWKER0U=
=yRi5
-----END PGP SIGNATURE-----