Buffer overflow in FTP Server in Apple Mac OS X before 10.6.2 allows remote attackers to execute arbitrary code or cause a denial of service (daemon crash) via a CWD command specifying a pathname in a deeply nested hierarchy of directories, related to a "CWD command line tool."
http://www.vupen.com/english/advisories/2009/3184
http://www.securityfocus.com/bid/36956
http://support.apple.com/kb/HT3937
http://lists.apple.com/archives/security-announce/2009/Nov/msg00000.html