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
       
Overview

   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
   machine.
   
   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
   vulnerability:
   
          http://www.microsoft.com/technet/security/bulletin/MS01-023.asp
          
   This vulnerability has been assigned the identifier CAN-2001-0241 by
   the Common Vulnerabilities and Exposures (CVE) group:
   
          http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2001-0241
          
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
   
          http://www.microsoft.com/Downloads/Release.asp?ReleaseID=29321
          
   Additional advice on securing IIS web servers is available from
   
          http://www.microsoft.com/technet/security/iis5chk.asp
          http://www.microsoft.com/technet/security/tools.asp
          
Appendix A. Vendor Information

Microsoft Corporation

   The following documents regarding this vulnerability are available
   from Microsoft:
   
          http://www.microsoft.com/technet/security/bulletin/MS01-023.asp
          
References

    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,
       http://www.kb.cert.org/vuls/id/516648
       
   Authors:  Chad Dougherty, Shawn Hernan.
   ______________________________________________________________________
   
   This document is available from:
   http://www.cert.org/advisories/CA-2001-10.html
   ______________________________________________________________________
   
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
          U.S.A.
          
   CERT/CC personnel answer the hotline 08:00-17:00 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
   
   http://www.cert.org/CERT_PGP.key
       
   If you prefer to use DES, please call the CERT hotline for more
   information.
   
    Getting security information
    
   CERT publications and other security information are available from
   our web site
   
   http://www.cert.org/
       
   To subscribe to the CERT mailing list for advisories and bulletins,
   send email to majordomo@cert.org. Please include in the body of your
   message
   
   subscribe cert-advisory
   
   * "CERT" and "CERT Coordination Center" are registered in the U.S.
   Patent and Trademark Office.
   ______________________________________________________________________
   
   NO WARRANTY
   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