Secure Shell (SSH) 2 in Cisco IOS 12.0 through 12.3 allows remote attackers to cause a denial of service (device reload) (1) via a username that contains a domain name when using a TACACS+ server to authenticate, (2) when a new SSH session is in the login phase and a currently logged in user issues a send command, or (3) when IOS is logging messages and an SSH session is terminated while the server is sending data.
Cisco IOS 12.0S, 12.2, and 12.3, with Open Shortest Path First (OSPF) enabled, allows remote attackers to cause a denial of service (device reload) via a malformed OSPF packet.