Directory traversal vulnerability in SmartSoft Ltd SmartFTP Client 4.0.1124.0, and possibly other versions before 4.0 Build 1133, allows remote FTP servers to overwrite arbitrary files via a "..\" (dot dot backslash) in a filename. NOTE: some of these details are obtained from third party information.
http://www.smartftp.com/forums/index.php?/topic/16425-smartftp-client-40-change-log/
http://www.htbridge.ch/advisory/directory_traversal_in_smartftp.html