The default configuration of Terminal in Apple Mac OS X 10.6 before 10.6.7 uses SSH protocol version 1 within the New Remote Connection dialog, which might make it easier for man-in-the-middle attackers to spoof SSH servers by leveraging protocol vulnerabilities.
http://support.apple.com/kb/HT4581
http://lists.apple.com/archives/security-announce/2011/Mar/msg00006.html