TechNet Home > TechNet Security > Bulletins

Microsoft Security Bulletin (MS00-013)

Patch Available for "Misordered Windows Media Services Handshake" Vulnerability

Originally Posted: February 23, 2000

Summary

Microsoft has released a patch that eliminates a security vulnerability in Microsoft® Windows Media Services. The vulnerability could allow denial of service attacks against a streaming media server.

Frequently asked questions regarding this vulnerability and the patch can be found at http://www.microsoft.com/technet/security/bulletin/fq00-013.mspx

Top of section

General Information

Issue

The handshake sequence between a Windows Media server and a Windows Media Player is asynchronous, because certain resource requests are dependent on the successful completion of previous ones. If the client-side handshake packets are sent in a particular misordered sequence, with certain timing constraints, the server will attempt to use a resource before it has been initialized and will fail catastrophically, causing the Windows Media Unicast Service to crash.

The Windows Media Unicast Service can be put back into normal operating condition by restarting the service, but any sessions that were in effect at the time of the crash would need to be restarted.

Affected Software Versions

•

Microsoft Windows Media Services 4.0 and 4.1

Note Windows NT Server 4.0 customers should upgrade their Windows Media Services installation to Windows Media Services 4.1 before applying the patch. Windows 2000 Server includes Windows Media Services 4.1, so the patch can be applied directly to this configuration

Vulnerability Identifier: CVE-2000-0211

Top of section

Patch Availability

•

Windows NT Server 4.0:

http://download.microsoft.com/download/winmediatech40/
Update/4954/NT4/EN-US/WMSU4954_NT4.EXE

•

Windows 2000 Server:

http://download.microsoft.com/download/winmediatech40/
Update/4954/NT5/EN-US/WMSU4954_Win2000.EXE

Note Additional security patches are available at the Microsoft Download Center

Top of section

More Information

Please see the following references for more information related to this issue.

•	Frequently Asked Questions: Microsoft Security Bulletin MS00-013, http://www.microsoft.com/technet/security/bulletin/fq00-013.mspx.
•	Microsoft Knowledge Base (KB) article, 253943, Title Misordered Windows Media Services Handshake Vulnerability, http://support.microsoft.com/default.aspx?scid=kb;en-us;253943
•	Microsoft TechNet Security Web site, http://www.microsoft.com/technet/security/default.mspx.

Obtaining Support on this Issue

This is a fully supported patch. Information on contacting Microsoft Technical Support is available at http://support.microsoft.com/contactussupport/?ws=support.

Acknowledgments

Microsoft thanks Kit Knox for bringing this issue to our attention.

Revisions

•	February 23, 2000: Bulletin Created.

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Top of section

Top of page