Microsoft Windows NAT Helper Components (ipnathlp.dll) on Windows XP SP2, when Internet Connection Sharing is enabled, allows remote attackers to cause a denial of service (svchost.exe crash) via a malformed DNS query, which results in a null pointer dereference.
https://www.exploit-db.com/exploits/2672
https://exchange.xforce.ibmcloud.com/vulnerabilities/29917
http://www.vupen.com/english/advisories/2006/4248
http://www.securityfocus.com/bid/20804
http://securitytracker.com/id?1017133