The TCP/IP implementation in Microsoft Windows Vista Gold, SP1, and SP2 and Server 2008 Gold and SP2, when a custom network driver is used, does not properly handle local fragmentation of Encapsulating Security Payload (ESP) over UDP packets, which allows remote attackers to execute arbitrary code via crafted packets, aka "Header MDL Fragmentation Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A8400
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2010/ms10-009