-----BEGIN PGP SIGNED MESSAGE----- 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 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 2003 Carnegie Mellon University. Revision History July 17, 2003: Initial release -----BEGIN PGP SIGNATURE----- Version: PGP 6.5.8 iQCVAwUBPxYuDmjtSoHZUTs5AQFv7wP/WetxU0XdObqmC02+lOSG/aR1lGsMpB0i 9AAilcA21Dd/VO/cD8cAiAnb/pavd7NF+uXM8xDdlCTB7ypME5pKFOn6zk1sc9L9 G+9iOSqFUQbnM496CQRdz+UpDYNN4dT9/bgt239Bpyh2gxGxGIxKKN/cUCQ2kGxr yjsZSjp9hME= =ao29 -----END PGP SIGNATURE-----