Summary

Microsoft has released a patch that eliminates a security vulnerability that could cause certain email applications to fail, requiring the user to restart the e-mail client to resume normal operation.

Frequently asked questions regarding this vulnerability and the patch can be found at http://www.microsoft.com/technet/security/bulletin/fq00-068.asp

Issue

OCX controls are containers that can hold multiple ActiveX controls. A particular OCX control, associated with Windows Media Player, could be used in a denial of service attack against RTF-enabled e-mail clients such as Microsoft« Outlook and Outlook Express. If the affected control were programmatically embedded into an RTF mail and then sent to another user, the user’s mail client would fail when he closed the mail.

The vulnerability would not cause any lasting effects. The user could resume normal operation by restarting the mail client and deleting the affected mail. Although the affected OCX control is associated with Windows Media Player, it poses no threat to it – the vulnerability could only be used to attack e-mail clients.

Affected Software Versions

Media Player OCX as part of Microsoft Windows Media Player 7, and only when installed on systems running Outlook or Outlook Express.

Note: The vulnerability only occurs if both Windows Media Player 7 and an affected e-mail client (Outlook or Outlook Express) are installed on the same machine. Machines that only fulfill one of these conditions are not affected.

Patch Availability

Microsoft Windows Media Player 7
http://www.microsoft.com/Downloads/Release.asp?ReleaseID=24421

Note Additional security patches are available at the Microsoft Download Center

More Information

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

Frequently Asked Questions: Microsoft Security Bulletin MS00-068, http://www.microsoft.com/technet/security/bulletin/fq00-068.asp
Microsoft Knowledge Base article Q274303 discusses this issue and will be available soon.
Microsoft TechNet Security web site, http://www.microsoft.com/technet/security/default.asp

Obtaining Support on this Issue

This is a fully supported patch. Information on contacting Microsoft Product Support Services is available at http://support.microsoft.com/support/contact/default.asp.

Acknowledgments

Microsoft thanks Luciano Martins of USSR Labs (www.ussrback.com) for reporting this issue to us and working with us to protect customers.

Revisions

September 26, 2000: Bulletin Created.

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