Cisco Security Advisory – Remote Authentication Dial In User Service (RADIUS) authentication on a device that is running certain versions of Cisco Internetworking Operating System (IOS) and configured with a fallback method to none can be bypassed.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/38368/cisco-sa-20050629-aaa.txt
Source: https://packetstormsecurity.com/files/38368/Cisco-Security-Advisory-20050629-aaa.html