Microsoft has made a patch available for the Windows Media Player 6.4 and 7 "Buffer Overrun Vulnerability." This vulnerability is a variant of the buffer overrun vulnerability that is described in the following Microsoft Security Bulletin: Windows Media Player supports the use of .asx files so you can play streaming media that resides on intranet or Internet sites. However, the code that parses .asx files has an unchecked buffer, and this could potentially enable a malicious user to run code on another user's computer. The attacker could either send an affected file to another user and entice the user to run or preview it, or the attacker could host such a file on a Web site and cause it to start automatically whenever a user visited the site. The code could take any action on the computer that the legitimate user could take.

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Mitigating Factors

•	The attacker would need the ability to entice the user into either visiting a Web site that is under the attacker's control, or open an HTML e-mail message the attacker had prepared.
•	The attacker would need to know the specific operating system that the user was running to tailor the attack code properly. If the attacker made an incorrect guess about the user's operating system, the attack would cause the user's program to stop responding (hang), but not run code of the attacker's choice.

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Windows Media Player 7

To resolve this problem, view the following Microsoft Web site to upgrade to Windows Media Player 7.1 or later: For more information about Windows Media Technologies, please see the following Microsoft Web site:

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Windows Media Player 6.4

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that you determine are at risk of attack. Evaluate the computer's physical accessibility, network and Internet connectivity, and other factors to determine the degree of risk to the computer. See the associated Microsoft Security Bulletin (http://www.microsoft.com/technet/security/bulletin/ms01-029.asp) to help determine the degree of risk. This hotfix may receive additional testing. If the computer is sufficiently at risk, we recommend that you apply this hotfix now.

To resolve this problem immediately, download the hotfix by following the instructions later in this article or contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site: Note In special cases, charges that are ordinarily incurred for support calls may be canceled, if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The following file is available for download from the Microsoft Download Center:
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file. The English version of this fix should have the following file attributes or later:

   Date        Time    Version     Size     File name
   -----------------------------------------------------
   01/31/2001  11:33p                  516  Control.xml
   05/03/2001  04:24p  6.4.7.1117  498,448  Dxm550.dll
   05/03/2001  05:02p  6.4.7.1117  525,312  Dxmasf.dll
   05/11/2001  09:28a                5,891  Eula.txt
   04/20/2001  04:33p  4.1.0.3925   28,160  Laprxy.dll
   04/20/2001  04:33p  4.1.0.3925   68,608  Logagent.exe
   04/05/2001  04:09p  6.4.9.1116  844,048  Msdxm.ocx
   04/05/2001  04:10p  6.4.7.1116  845,584  Msdxm550.ocx
   05/01/2001  05:08p  7.1.0.3055  274,432  Setup_wm.exe
   04/20/2001  01:14p  4.1.0.3925  251,904  Strmdll.dll
   12/06/2000  12:43a  7.0.0.1958   65,592  Wminf.exe
   05/08/2001  03:10p                8,636  Wmqfe.cat
   04/25/2001  04:10p                2,439  Wmqfe.inf
				

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Windows Media Player 7

Microsoft has confirmed that this problem may cause a degree of security vulnerability in Windows Media Player 7. This problem was first corrected in Windows Media Player 7.1 (http://download.microsoft.com/download/winmediaplayer/wmp71/7.1/w982kme/en-us/mp71.exe).

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Windows Media Player 6.4

Microsoft has confirmed that this problem may cause a degree of security vulnerability in Windows Media Player 6.4.

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For additional information about this vulnerability and what else this patch fixes, please see the following Microsoft web site:

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