The vulnerability of the Cisco IOS operating system allows a malicious individual to establish a network connection using the TELNET protocol.

The Cisco IOS operating system of telecommunications equipment does not recognize the keyword “vrf-also” during the execution of the “access-class” command. This allows a malicious intruder to establish a network connection using the TELNET protocol...

CVE-2012-0339

Cisco IOS 12.2 through 12.4 and 15.0 does not recognize the vrf-also keyword during enforcement of access-class commands, which allows remote attackers to establish TELNET connections from arbitrary source IP addresses via a standard TELNET client, aka Bug ID CSCsi77774...