Memory leak in Secure Shell (SSH) in Cisco IOS 12.0 through 12.3, when authenticating against a TACACS+ server, allows remote attackers to cause a denial of service (memory consumption) via an incorrect username or password.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5687
https://exchange.xforce.ibmcloud.com/vulnerabilities/19991
http://www.securitytracker.com/alerts/2005/Apr/1013655.html
http://www.securityfocus.com/bid/13042
http://www.cisco.com/warp/public/707/cisco-sa-20050406-ssh.shtml