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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
   ______________________________________________________________________

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   Revision History
May 02, 2001: Initial Release

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