Unspecified vulnerability in the Wireless LAN Controller (WLC) TSEC driver in the Cisco 4400 WLC, Cisco Catalyst 6500 and 7600 Wireless Services Module (WiSM), and Cisco Catalyst 3750 Integrated Wireless LAN Controller with software 4.x before 4.2.176.0 and 5.x before 5.1 allows remote attackers to cause a denial of service (device crash or hang) via unknown IP packets.