-----BEGIN PGP SIGNED MESSAGE-----

- ----------------------------------------------------------------------
Title:      Windows Media Player .NSC Processor Contains Unchecked
            Buffer
Date:       26 July 2001
Software:   Windows Media Player 6.4, 7, and 7.1
Impact:     Run code of attacker's choice.
Bulletin:   MS01-042

Microsoft encourages customers to review the Security Bulletin at: 
http://www.microsoft.com/technet/security/bulletin/MS01-042.asp.
- ----------------------------------------------------------------------

Issue:
======
Windows Media Player provides support for audio and video streaming. 
Streaming media channels can be configured by using Windows Media 
Station (.NSC) files. An unchecked buffer exists in the functionality
used to process Windows Media Station files. This unchecked buffer 
could potentially allow an attacker to run code of his choice on the 
machine of another user. The attacker could either send a specially 
malformed file to another user and entice her to run or preview it,
or 
he could host such a file on a web site and cause it to launch 
automatically whenever a user visited the site. The code could take
any action on the machine that the legitimate user himself could
take.

Mitigating Factors:
====================
 - Customers who have applied the Outlook E-mail Security Update
   (OESU) for Outlook 2000 or are running Outlook XP, which has the
   OESU functionality built-in, are automatically protected against
   HTML e-mail based attempts to exploit this vulnerability.
 
 - For others not in the above categories, the attacker would have to
   entice the potential victim to visit a web site he controlled, or
to
   open an HTML e-mail he had sent. 

 - The attacker would need to know the specific operating system that
   the user was running in order to tailor the attack code properly;
if
   the attacker made an incorrect guess about the user's operating
   system platform, the attack would crash the user's Windows Media
   Player session, but not run code of the attacker's choice. 

Patch Availability:
===================
 - A patch is available to fix this vulnerability. Please read the 
   Security Bulletin
   http://www.microsoft.com/technet/security/bulletin/ms01-042.asp
   for information on obtaining this patch.

- ---------------------------------------------------------------------

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.

-----BEGIN PGP SIGNATURE-----
Version: PGP Personal Privacy 6.5.3

iQEVAwUBO2C9XI0ZSRQxA/UrAQGgBQf8CbzjtFGnQTiTt6yEngvhBX8pmq/C2VGE
NMFl6VvHyqtMXEIkkV1RE1RQOVDSlniWIhI9Ep+wUqYi+BUeG9PDgzgjAjiKXmBV
yv/RQalSgQjMuLz2d9JflTTyOudadDbyzrix0QbLwspvBbR1U6JM4Jeh0B7xn1p2
wp2jsuNlRX9byQJmjeMf64DyF51nqi2rdjG/ZoJ0m562JtzbLLQLU7w3o1xFKKsL
hXd2YvfRUmNb+M0q9RZzThnpcJUXj9TTnlkq5GZC3uYi3SxmgqyD8bx2qsI6Bwq9
9gpZ5NQMvkcdGYMqy07eU8zI12f9KWvxJcxZbj0Oj5ahbTWtSDtY/w==
=a1bP
-----END PGP SIGNATURE-----