Public Vulnerability Reports

Microsoft Distributed Transaction Controller TIP DoS Vulnerability



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.


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

The following commands can be sent over TCP port 3372 to force the DTC
service to connect to an arbitrary host and process commands:



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.


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.


iDEFENSE is currently unaware of any workarounds for this issue.


The vendor security advisory and appropriate patches are available at:


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 (, which standardizes names for
security problems.


03/23/2005 Initial vendor notification
03/23/2005 Initial vendor response
10/11/2005 Coordinated public disclosure


The discoverer of this vulnerability wishes to remain anonymous.

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Copyright © 2005 Verisign, Inc.

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