Microsoft Security Bulletin MS03-019: Flaw in ISAPI Extension for Windows Media Services Could Cause Code Execution (817772)

["Microsoft" <0_48520_04BF067D-4CF8-4245-B5C1-58573E5746A8_US () Newsletters Microsoft com>]

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

- -------------------------------------------------------------------
Title:      Flaw in ISAPI Extension for Windows Media Services   
            Could Cause Code Execution (817772)
Date:       28 May 2003
Software:   Microsoft(r) Windows NT(r) 4.0, and Windows(r) 2000
Impact:     Allow an attacker to execute code of their choice
Max Risk:   Important
Bulletin:   MS03-019

Microsoft encourages customers to review the Security Bulletins at: 
http://www.microsoft.com/technet/security/bulletin/MS03-019.asp
http://www.microsoft.com/security/security_bulletins/ms03-019.asp
- -------------------------------------------------------------------

Reason for Revision:
====================

On May 28th, Microsoft released the initial version of this 
bulletin, rating the severity of the vulnerability as Moderate. 
Subsequent to that release we have determined that the actions an 
attacker could take as a result of exploiting this vulnerability 
could include the ability to execute arbitrary code. As a result 
Microsoft has reissued this bulletin and changed the severity 
rating to Important. The original corrects the vulnerability and is 
not being re-released. 

Issue:
======
Microsoft Windows Media Services is a feature of Microsoft Windows 
2000 Server, Advanced Server, and Datacenter Server and is also 
available as a downloadable version for Windows NT 4.0 Server. 
Windows Media Services contain support for a method of delivering 
media content to clients across a network known as multicast 
streaming. In multicast streaming however, the server has no 
connection or knowledge of the clients that may be receiving the 
stream coming from the server. To facilitate logging of client 
information for the server Windows 2000 includes a capability 
specifically designed for that purpose. To help with this problem, 
Windows 2000 includes logging capabilities for multicast and 
unicast transmissions.

This capability is implemented as an Internet Services Application 
Programming Interface (ISAPI) extension - nsiislog.dll. When 
Windows Media Services are installed in Windows NT 4.0 Server or 
added through add/remove programs to Windows 2000, nsiislog.dll is 
installed to the Internet Information Services (IIS) Scripts 
directory on the server. 

There is a flaw in the way in which nsiislog.dll processes incoming 
requests. A vulnerability exists because an attacker could send 
specially formed communications to the server that could cause IIS 
to fail or execute code on the user's system.

Windows Media Services is not installed by default on Windows 2000, 
and must be downloaded to install on Windows NT 4.0. An attacker 
attempting to exploit this vulnerability would have to be aware 
which computers on the network had Windows Media Services installed 
on it and send a specific request to that server. 


Mitigating Factors:
====================
 - Windows Media Services 4.1 is not installed by default on 
Windows 2000, and must be downloaded to install on Windows NT 4.0.
 - Windows Media Services are not available for Windows 2000 
Professional or Windows NT 4.0 Workstation 
 - The attacker would have to know which server on the network 
Windows Media Services had been installed on.  

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/ms03-019.asp
http://www.microsoft.com/security/security_bulletins/ms03-019.asp
   
   for information on obtaining this patch.

Acknowledgment:
===============
 - Brett Moore (brett () softwarecreations co nz)

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

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 7.1

iQEVAwUBPte/7I0ZSRQxA/UrAQHPlwf/Tj5LV/X1JyNN8ioCm06pvrbM7PWJDq2W
22hDXp6L9QnBmaCKEwsznkE1p43tqEm14D5EvGiunuCTRqT5kB57xG6rq7u6uuyh
GnTnPtGDsvKf1PuImARd+jYowwoQBmxouNfuNz0PVqnCbEfxXMZQRyZsWyqpWb6+
+tfB9stg0LlPij/6Rf34xpSQEptzKHkuv4wACiNEk6SOENvuO5YfakfhWb7+1pSt
jJT0MaStts4O2hPKoRKNW8t4JhpDScfYZUy9OQV7I+221LT/MQNDc4guKFLvDZh4
polZobWlPyw2Yu+bNH9wDbm0EIrAQm7cOfjSN77brr8VuuxjtFOmHg==
=8a7L
-----END PGP SIGNATURE-----


*******************************************************************

You have received this e-mail bulletin because of your subscription to the Microsoft Product Security Notification 
Service.  For more information on this service, please visit http://www.microsoft.com/technet/security/notify.asp.
 
To verify the digital signature on this bulletin, please download our PGP key at 
http://www.microsoft.com/technet/security/notify.asp.
 
To unsubscribe from the Microsoft Security Notification Service, please visit the Microsoft Profile Center at 
http://register.microsoft.com/regsys/pic.asp 
 
If you do not wish to use Microsoft Passport, you can unsubscribe from the Microsoft Security Notification Service via 
email as described below:
Reply to this message with the word UNSUBSCRIBE in the Subject line.
 
For security-related information about Microsoft products, please visit the Microsoft Security Advisor web site at 
http://www.microsoft.com/security.