The Cisco Wireless LAN Controller (WLC), Cisco Catalyst 6500 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 5.2 allow remote attackers to cause a denial of service (web authentication outage or device reload) via unspecified network traffic, as demonstrated by a vulnerability scanner.