AUSCERT External Security Bulletin Redistribution

                 ESB-2001.185 -- CERT Advisory CA-2001-10
            Buffer Overflow Vulnerability in Microsoft IIS 5.0
                                4 May 2001


        AusCERT Security Bulletin Summary

Product:                Windows 2000 Server with IIS 5.0
                        Windows 2000 Advanced Server with IIS 5.0
                        Windows 2000 Datacenter Server with IIS 5.0
Vendor:                 Microsoft
Operating System:       Windows 2000
Impact:                 Administrator Compromise
Access Required:        Remote

Ref:                    AL-2001.07

- --------------------------BEGIN INCLUDED TEXT--------------------


CERT Advisory CA-2001-10 Buffer Overflow Vulnerability in Microsoft IIS 5.0

   Original release date: May 02, 2001
   Last revised: --
   Source: CERT/CC

   A complete revision history is at the end of this file.

Systems Affected

     * Systems running Microsoft Windows 2000 with IIS 5.0 enabled


   A vulnerability exists in Microsoft IIS 5.0 running on Windows 2000
   that allows a remote intruder to run arbitrary code on the victim
   machine, allowing them to gain complete administrative control of the

   A proof-of-concept exploit is publicly available for this
   vulnerability, which increases the urgency that system administrators
   apply the patch.

I. Description

   Windows 2000 includes support for the Internet Printing Protocol (IPP)
   via an ISAPI extension. According to Microsoft, this extension is
   installed by default on all Windows 2000 systems, but it is only
   accesible through IIS 5.0. The IPP extension contains a buffer
   overflow that could be used by an attacker to execute arbitrary code
   in the Local System security context, essentially giving the attacker
   compete control of the system. This vulnerability was discovered by
   eEye Digital Security.

   Microsoft has issued the following bulletin regarding this


   This vulnerability has been assigned the identifier CAN-2001-0241 by
   the Common Vulnerabilities and Exposures (CVE) group:


II. Impact

   Anyone who can reach a vulnerable web server can execute arbitrary
   code in the Local System security context, resulting in the intruder
   gaining complete control of the system. Note that this may be
   significantly more serious than a simple "web defacement."

III. Solution

Apply a patch from your vendor

   A patch is available from Microsoft at


   Additional advice on securing IIS web servers is available from


Appendix A. Vendor Information

Microsoft Corporation

   The following documents regarding this vulnerability are available
   from Microsoft:



    1. VU#516648: Microsoft Windows 2000/Internet Information Server
       (IIS) 5.0 Internet Printing Protocol (IPP) ISAPI contains buffer
       overflow, CERT/CC, 05/02/2001,

   Authors:  Chad Dougherty, Shawn Hernan.

   This document is available from:

CERT/CC Contact Information

   Email: cert@cert.org
          Phone: +1 412-268-7090 (24-hour hotline)
          Fax: +1 412-268-6989
          Postal address:
          CERT Coordination Center
          Software Engineering Institute
          Carnegie Mellon University
          Pittsburgh PA 15213-3890

   CERT personnel answer the hotline 08:00-20:00 EST(GMT-5) / EDT(GMT-4)
   Monday through Friday; they are on call for emergencies during other
   hours, on U.S. holidays, and on weekends.

    Using encryption

   We strongly urge you to encrypt sensitive information sent by email.
   Our public PGP key is available from


   If you prefer to use DES, please call the CERT hotline for more

    Getting security information

   CERT publications and other security information are available from
   our web site


   To subscribe to the CERT mailing list for advisories and bulletins,
   send email to majordomo@cert.org. Please include in the body of your

   subscribe cert-advisory

   * "CERT" and "CERT Coordination Center" are registered in the U.S.
   Patent and Trademark Office.

   Any material furnished by Carnegie Mellon University and the Software
   Engineering Institute is furnished on an "as is" basis. Carnegie
   Mellon University makes no warranties of any kind, either expressed or
   implied as to any matter including, but not limited to, warranty of
   fitness for a particular purpose or merchantability, exclusivity or
   results obtained from use of the material. Carnegie Mellon University
   does not make any warranty of any kind with respect to freedom from
   patent, trademark, or copyright infringement.

   Conditions for use, disclaimers, and sponsorship information

   Copyright 2001 Carnegie Mellon University.

   Revision History
May 02, 2001: Initial Release

Version: PGPfreeware 5.0i for non-commercial use
Charset: noconv


- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content.  The decision to use any or all of this information is
the responsibility of each user or organisation, and should be done so in
accordance with site policies and procedures.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the original authors to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:


If you believe that your system has been compromised, contact AusCERT or
your representative in FIRST (Forum of Incident Response and Security

Internet Email: auscert@auscert.org.au
Facsimile:	(07) 3365 7031
Telephone:	(07) 3365 4417 (International: +61 7 3365 4417)
		AusCERT personnel answer during Queensland business hours
		which are GMT+10:00 (AEST).
		On call after hours for emergencies.

Version: 2.6.3i
Charset: noconv
Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key