CVE-2009-2818
Adaptive Firewall in Apple Mac OS X before 10.6.2 does not properly handle invalid usernames in SSH login attempts, which makes it easier for remote attackers to obtain login access via a brute-force attack (aka dictionary attack).
Date published : 2009-11-10
http://lists.apple.com/archives/security-announce/2009/Nov/msg00000.html