Web Cache Control Protocol (WCCP) in Cisco Cache Engine for Cisco IOS 11.2 and earlier does not use authentication, which allows remote attackers to redirect HTTP traffic to arbitrary hosts via WCCP packets to UDP port 2048.

Vulnerability in Cisco IOS 11.1 through 11.3 with distributed fast switching (DFS) enabled allows remote attackers to bypass certain access control lists when the router switches traffic from a DFS-enabled input interface to an output interface with a logical subinterface, as described by Cisco bug CSCdk43862.

Attackers can crash a Cisco IOS router or device, provided they can get to an interactive prompt (such as a login). This applies to some IOS 9.x, 10.x, and 11.x releases.