Advisory CA-2001-10

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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.

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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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