The MSDTC (Microsoft Distributed Transaction Service Coordinator) for Microsoft Windows 2000, Microsoft IIS 5.0 and SQL Server 6.5 through SQL 2000 0.0 allows remote attackers to cause a denial of service (crash or hang) via malformed (random) input.
http://www.securityfocus.com/bid/4006
http://www.iss.net/security_center/static/8046.php