The Windows NAT Driver (aka winnat) service in Microsoft Windows Server 2012 does not properly validate memory addresses during the processing of ICMP packets, which allows remote attackers to cause a denial of service (memory corruption and system hang) via crafted packets, aka "Windows NAT Denial of Service Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A18199
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2013/ms13-064