The FTP Server in Cisco IOS 11.3 through 12.4 does not properly check user authorization, which allows remote attackers to execute arbitrary code, and have other impact including reading startup-config, as demonstrated by a crafted MKD command that involves access to a VTY device and overflows a buffer, aka bug ID CSCek55259.

Cisco IOS 12.0 through 12.4 and IOS XR before 3.2, with IPv6 enabled, allows remote attackers on a local network segment to cause a denial of service (device reload) and possibly execute arbitrary code via a crafted IPv6 packet.

Cisco IOS 12.2T through 12.4 allows remote attackers to bypass Authentication, Authorization, and Accounting (AAA) RADIUS authentication, if the fallback method is set to none, via a long username.