Internet Key Exchange (IKE) version 1 protocol, as implemented on Cisco IOS, VPN 3000 Concentrators, and PIX firewalls, allows remote attackers to cause a denial of service (resource exhaustion) via a flood of IKE Phase-1 packets that exceed the session expiration rate. NOTE: it has been argued that this is due to a design weakness of the IKE version 1 protocol, in which case other vendors and implementations would also be affected.
The web interface on Cisco IOS 12.3(8)JA and 12.3(8)JA1, as used on the Cisco Wireless Access Point and Wireless Bridge, reconfigures itself when it is changed to use the "Local User List Only (Individual Passwords)" setting, which removes all security and password configurations and allows remote attackers to access the system.