The Network Threat Protection module in the Manager component in Symantec Endpoint Protection (SEP) 11.0.600x through 11.0.700x on Windows Server 2003 allows remote attackers to cause a denial of service (web-server outage, or daemon crash or hang) via a flood of packets that triggers automated blocking of network traffic.
http://www.securitytracker.com/id?1027092
http://www.securityfocus.com/bid/50358
http://www.kb.cert.org/vuls/id/149070