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Title: Flaw In Windows Media Player May Allow Media Library
Access (819639)
Date: 25 June 2003
Software: Microsoft(r) Windows(r) Media Player 9 Series
Impact: Information disclosure
Max Risk: Moderate
Bulletin: MS03-021

Microsoft encourages customers to review the Security Bulletins at:
http://www.microsoft.com/technet/security/bulletin/MS03-021.asp
http://www.microsoft.com/security/security_bulletins/ms03-021.asp

---

Issue:

An ActiveX control included with Windows Media Player 9 Series
allows Web page authors to create Web pages that can play media and
provide a user interface by which the user can control playback.
When a user visits a Web page with embedded media, the ActiveX
control provides a user interface that allows the user to take such
actions as pausing or rewinding the media.

A flaw exists in the way in which the ActiveX control provides
access to information on the user's computer. A vulnerability exists
because an attacker could invoke the ActiveX control from script
code, which would allow the attacker to view and manipulate metadata
contained in the media library on the user's computer.

To exploit this flaw, an attacker would have to host a malicious Web
site that contained a Web page designed to exploit this
vulnerability, and then persuade a user to visit that site-an
attacker would have no way to force a user to the site. An attacker
could also embed a link to the malicious site in an HTML e-mail and
send it to the user. After the user previewed or opened the e-mail,
the malicious site could be visited automatically without further
user interaction.

The attacker would only have access to manipulate the media library
on the user's computer. The attacker would not be able to browse the
user's hard disk and would not have access to passwords or encrypted
data. The attacker would not be able to modify files on the user's
hard disk, but could modify the contents of any Media Library
entries associated with those files. The attacker might also be able
to determine the user name of the logged-on user by examining the
directory paths to media files.

Mitigating Factors:

• By default, Internet Explorer on Windows Server 2003 runs in
  Enhanced Security Configuration. This default configuration of
  Internet Explorer blocks this attack.
• The attacker could only gain access to information contained in
  the Windows Media Library
• The attacker would not be able to execute code on the system or
  delete files on the user's hard disk.

Risk Rating:

Moderate

Patch Availability:

• A patch is available to fix this vulnerability. Please read the
  Security Bulletins at

http://www.microsoft.com/technet/security/bulletin/ms03-021.asp
http://www.microsoft.com/security/security_bulletins/ms03-021.asp

for information on obtaining this patch.

Acknowledgment:

• Jelmer ([email protected])

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IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE
FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
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OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

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