CERT Advisory CA-2001-37 Buffer Overflow in UPnP Service On Microsoft Windows

From: CERT Advisory (cert-advisory@cert.org)
Date: 12/21/01

Date: Thu, 20 Dec 2001 20:18:59 -0500 (EST)
From: CERT Advisory <cert-advisory@cert.org>
To: cert-advisory@cert.org


CERT Advisory CA-2001-37 Buffer Overflow in UPnP Service On Microsoft Windows

   Original release date: December 20, 2001
   Last revised: --
   Source: CERT/CC

   A complete revision history can be found at the end of this file.

Systems Affected

     * Microsoft Windows XP
     * Microsoft Windows ME
     * Microsoft Windows 98
     * Microsoft Windows 98SE


   Vulnerabilities in software included by default on Microsoft Windows
   XP, and optionally on Windows ME and Windows 98, may allow an intruder
   to execute arbitrary code on vulnerable systems, to launch
   denial-of-service attacks against vulnerable systems, or to use
   vulnerable systems to launch denial-of-service attacks against
   third-party systems.

I. Description

   There is a vulnerability in the Universal Plug and Play (UPnP) service
   on Microsoft Windows XP and Microsoft Windows ME that could permit an
   intruder to execute arbitrary code with administrative privileges on a
   vulnerable system. The UPnP service is enabled by default on XP.
   Microsoft does not ship Windows ME with UPnP enabled by default, but
   some PC manufacturers do. UPnP may be optionally installed on Windows
   98 and Windows 98SE. This vulnerability was discovered by Eeye Digital
   Security. For more information, see


   Universal Plug and Play (UPnP) is a set of protocols that allow
   computer systems and network devices to work together with little or
   no prior configuration.

   One vulnerability is a buffer overflow in the code that handles UPnP
   NOTIFY directives. This vulnerability permits an intruder to send a
   malicious NOTIFY directive to a vulnerable computer and cause the
   computer to run code of the intruder's choice. The code will run with
   full privileges on all vulnerable systems, including Windows XP. This
   can permit an attacker to take complete control of the system.

   A second vulnerability in the Microsoft Windows implementation of UPnP
   could allow an intruder to consume memory and processor time on
   vulnerable systems, resulting in performance degradation. Variations
   on this problem can allow an intruder to use a vulnerable system to
   launch a denial-of-service attack against a third-party.

   For more information about these vulnerabilities, see


   These vulnerabilities have been assigned the CVE identifiers
   CAN-2001-0876 and CAN-2001-0877, respectively.

II. Impact

   Intruders can gain complete control of vulnerable systems, or
   interrupt the normal operation of vulnerable systems.

III. Solution

Apply a patch from your vendor

   Microsoft has provided patch information in their bulletin. Please see
   MS01-059, available from


Block Access to UPnP Service

   Until a patch can be applied, you can reduce your exposure to this
   problem by blocking access to ports 1900 and 5000 at your network
   border. This does not eliminate your exposure to attacks originating
   from within your network, however.

   Note that Microsoft Internet Connection Firewall, which runs by
   default on Windows XP, does not provide complete protection against
   this attack. Specifically, an intruder can still use a broadcast or
   multicast address to reach the UPnP service on Microsoft Windows. On
   systems that don't require UPnP, it can be disabled.

   Author: Shawn V. Hernan

   This document is available from:

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   Revision History
December 20, 2001: Initial release

Version: PGP 6.5.8