Wing FTP Server before 4.1.1 allows remote authenticated users to cause a denial of service (daemon crash) via two zip commands.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2012-4654
http://www.wftpserver.com/serverhistory.htm
http://www.securityfocus.com/bid/55847
http://archives.neohapsis.com/archives/bugtraq/2012-10/0052.html