Microsoft Distributed Transaction Controller TIP DoS Vulnerability iDEFENSE Security Advisory 10.11.05 www.idefense.com/application/poi/display?id=320&type=vulnerabilities October 11, 2005 I. BACKGROUND The Distributed Transaction Controller provides a method for disparate processes to complete atomic transactions. The Transaction Internet Protocol (TIP) is one the ways that the DTC service can be accessed. This service is part of a standard installation on Windows NT 4.0, Windows 2000, Windows XP and Windows 2003. II. DESCRIPTION Remote exploitation of a denial of service vulnerability within various versions of Microsoft Corp.'s Windows operating system allows attackers to cause the msdtc.exe process to crash. The vulnerability specifically exists because of a flaw in processing responses from foreign servers. The DoS can be triggered by sending a command sequence that causes the DTC service to connect back to a hostile server. If the hostile server sends an unexpected protocol command during the reconnection request, the DTC service will throw an exception and exit. This attack can be used to kill the DTC service and prevent other applications from using the service to process transactions. The following commands can be sent over TCP port 3372 to force the DTC service to connect to an arbitrary host and process commands: IDENTIFY 3 3 DST_IP:DST_PORT/ANYID - PUSH SOMESTRING PREPARE RECONNECT III. ANALYSIS Successful exploitation of this vulnerability will cause applications requiring the MSDTC service to fail. One such service is Microsoft SQL Server. Any other applications that rely on clustering to be functional will also fail. This service should not be exposed to public networks, thus mitigating the risk of this vulnerability. IV. DETECTION iDEFENSE has confirmed the existence and exploitability of this vulnerability in Microsoft Windows 2000 SP4. All versions of Microsoft Windows with the vulnerable service running are suspected vulnerable. V. WORKAROUND iDEFENSE is currently unaware of any workarounds for this issue. VI. VENDOR RESPONSE The vendor security advisory and appropriate patches are available at: http://www.microsoft.com/technet/security/Bulletin/MS05-051.mspx VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CAN-2005-1979 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems. VIII. DISCLOSURE TIMELINE 03/23/2005 Initial vendor notification 03/23/2005 Initial vendor response 10/11/2005 Coordinated public disclosure IX. CREDIT The discoverer of this vulnerability wishes to remain anonymous. Get paid for vulnerability research http://www.idefense.com/poi/teams/vcp.jsp Free tools, research and upcoming events http://labs.idefense.com X. LEGAL NOTICES Copyright (c) 2005 iDEFENSE, Inc. Permission is granted for the redistribution of this alert electronically. It may not be edited in any way without the express written consent of iDEFENSE. If you wish to reprint the whole or any part of this alert in any other medium other than electronically, please email customerservice@private for permission. Disclaimer: The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.
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