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CERT Advisory CA-2003-16 Buffer Overflow in Microsoft RPC

   Original release date: July 17, 2003
   Last revised: --
   Source: CERT/CC

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

Systems Affected

     * Microsoft Windows NT 4.0
     * Microsoft Windows NT 4.0 Terminal Services Edition
     * Microsoft Windows 2000
     * Microsoft Windows XP
     * Microsoft Windows Server 2003

Overview

   A buffer overflow vulnerability exists in Microsoft's Remote Procedure
   Call  (RPC)  implementation.  A  remote  attacker  could  exploit this
   vulnerability to execute arbitrary code or cause a denial of service.

I. Description

   There   is  a  buffer  overflow  in  Microsoft's  RPC  implementation.
   According  to  Microsoft  Security  Bulletin  MS03-026,  "There  is  a
   vulnerability in the part of RPC that deals with message exchange over
   TCP/IP. The failure results because of incorrect handling of malformed
   messages.   This   particular   vulnerability  affects  a  Distributed
   Component  Object  Model  (DCOM)  interface with RPC, which listens on
   TCP/IP  port  135.  This  interface  handles  DCOM  object  activation
   requests  that  are  sent by client machines (such as Universal Naming
   Convention (UNC) paths) to the server."

   The CERT/CC is tracking this issue as VU#568148. This reference number
   corresponds to CVE candidate CAN-2003-0352.

II. Impact

   A   remote  attacker  could  exploit  this  vulnerability  to  execute
   arbitrary  code  with  Local System privileges or to cause a denial of
   service.

III. Solution

Apply a patch

   Apply  the  appropriate  patch  as  specified  by  Microsoft  Security
   Bulletin MS03-026.

Restrict access

   You  may  wish to block access from outside your network perimeter,
   specifically  by blocking access to port 135/TCP. This will limit your
   exposure  to attacks. However, blocking at the network perimeter would
   still  allow attackers within the perimeter of your network to exploit
   the  vulnerability.  It  is  important  to  understand  your network's
   configuration  and  service  requirements before deciding what changes
   are appropriate.
     _________________________________________________________________

   This  vulnerability  was  discovered  by  The  Last  Stage of Delirium
   Research  Group.  Microsoft  has published Microsoft Security Bulletin
   MS03-026, upon which this document is largely based.
     _________________________________________________________________

   Author: Ian A. Finlay
   ______________________________________________________________________

   This document is available from:
   http://www.cert.org/advisories/CA-2003-16.html
   ______________________________________________________________________

CERT/CC Contact Information

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          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.

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   ______________________________________________________________________

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   Engineering  Institute  is  furnished  on  an  "as is" basis. Carnegie
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   Conditions for use, disclaimers, and sponsorship information

   Copyright 2003 Carnegie Mellon University.

   Revision History
July 17, 2003:  Initial release

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