Microsoft Security Bulletin (MS00-086)

[Microsoft Product Security <secnotif () MICROSOFT COM>]

The following is a Security  Bulletin from the Microsoft Product Security
Notification Service.

Please do not  reply to this message,  as it was sent  from an unattended
mailbox.
                    ********************************

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

Microsoft Security Bulletin (MS00-086)
- --------------------------------------

Patch Available for "Web Server File Request Parsing" Vulnerability

Originally posted: November 06, 2000

Summary
=======
Microsoft has released a patch that eliminates a serious security
vulnerability in Microsoft(r) Internet Information Services  5.0. The
vulnerability could enable a malicious user to run operating system
commands on an affected web server.

Microsoft strongly urges all customers using IIS 5.0 to apply the
patch immediately. IIS 4.0 is not affected by the  vulnerability.

Frequently asked questions regarding this vulnerability and the patch
can be found at
http://www.microsoft.com/technet/security/bulletin/fq00-086.asp

Issue
=====
When IIS receives a valid request for an executable file, it passes
the name of the requested file to the underlying  operating system
for processing. However, due to an implementation flaw in IIS 5.0, it
is possible to create a  specially-malformed file request that
contains both a file name and one or more operating system commands.
Upon receiving  such a request, IIS 5.0 would pass the entire string
to the operating system, which would first process the file and then
execute the commands. The file would need to reside in a folder to
which the user had execute permissions, but it would not  necessarily
need to be an executable file.

The ability to execute operating system commands on the web server
would enable a malicious user to take virtually any action  that an
interactively-logged on user could take. Although this would not give
the malicious user administrative control over  the server, it would
nevertheless enable him to cause widespread damage. He could, for
instance, add, delete or change files  on the server, run code that
was already on the server, or upload code of his choice and run it.

Microsoft strongly recommends that all customers running IIS 5.0
immediately apply the patch for this vulnerability. The  patch also
eliminates the "Web Server Directory Traversal" vulnerability
discussed in Microsoft Security Bulletin MS00-078.  IIS 4.0 is not
affected by the vulnerability, and IIS 4.0 customers do not need to
take any action.

Affected Software Versions
==========================
 - Microsoft Internet Information Service 5.0

Note: IIS 4.0 is not affected by the vulnerability.

Patch Availability
==================
 - English:
   http://www.microsoft.com/Downloads/Release.asp?ReleaseID=25547
 - Simplified Chinese:
   http://www.microsoft.com/Downloads/Release.asp?ReleaseID=25580
 - Traditional Chinese:
   http://www.microsoft.com/Downloads/Release.asp?ReleaseID=25581
 - German:
   http://www.microsoft.com/Downloads/Release.asp?ReleaseID=25582
 - Japanese:
   http://www.microsoft.com/Downloads/Release.asp?ReleaseID=25583

Note: This patch can be applied atop system running either Windows
2000 Gold or Service Pack 1. It will be included in  Windows 2000
Service Pack 2.

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 MS00-086,
   http://www.microsoft.com/technet/security/bulletin/fq00-086.asp
 - Microsoft Knowledge Base article Q277873 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 NSFocus (http://www.nsfocus.com) for reporting this
issue to us and working with us to protect customers.

Revisions
=========
 - November 06, 2000: Bulletin Created.

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

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.

Last Updated November 06, 2000


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

iQEVAwUBOgcFAY0ZSRQxA/UrAQEN2wf+Ol4R3fCxzHhOnq5FUt88FrQSY/4E7Y1Y
Odf5fjNJja4Pt322teFSo3wWzmbmsfFgrJtD8Dk92O4FzIdj9TqQGrWEO1ixPPAr
3FLk+EqtaNTp9rA958OWDtdJr/9kS+uCtPWz9Yvy3Vb6pMcUJWpHF54HTxoQ3fb0
LpT1r6SlYo6Om1Ptu1qNACb2mAv4/KcJtXyj4zxne4zI1+lKJYdBQXvWFqnTNxm5
GTjwBrE8H83W3f/kFUhsZHVz1TAgNuklXuprLMsueS9Gsk4JLSQq7KEMuvY4I6VM
PQ+oiti4pz6lOSEnRe20NW5hIbuHJkoETd7xa7Ybv/c2qeZuuS9Auw==
=N/wR
-----END PGP SIGNATURE-----

   *******************************************************************
You have received  this e-mail bulletin as a result  of your registration
to  the   Microsoft  Product  Security  Notification   Service.  You  may
unsubscribe from this e-mail notification  service at any time by sending
an  e-mail  to  MICROSOFT_SECURITY-SIGNOFF-REQUEST () ANNOUNCE MICROSOFT COM
The subject line and message body are not used in processing the request,
and can be anything you like.

To verify the digital signature on this bulletin, please download our PGP
key at http://www.microsoft.com/technet/security/notify.asp.

For  more  information on  the  Microsoft  Security Notification  Service
please  visit  http://www.microsoft.com/technet/security/notify.asp.  For
security-related information  about Microsoft products, please  visit the
Microsoft Security Advisor web site at http://www.microsoft.com/security.