Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) do not properly determine the interfaces for which TELNET connections should be permitted, which allows remote authenticated users to bypass intended access restrictions via vectors involving the "lowest security level interface," aka Bug ID CSCsv40504.
https://exchange.xforce.ibmcloud.com/vulnerabilities/64601
http://www.securitytracker.com/id?1024963
http://www.securityfocus.com/bid/45767
http://www.cisco.com/en/US/docs/security/asa/asa82/release/notes/asarn82.pdf