Microsoft Windows XP SP2 and SP3, and Server 2003 SP1 and SP2, does not properly validate the option length field in Pragmatic General Multicast (PGM) packets, which allows remote attackers to cause a denial of service (infinite loop and system hang) via a crafted PGM packet, aka the "PGM Invalid Length Vulnerability."
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2008/ms08-036