WinFTP FTP Server 2.3.0, when passive (aka PASV) mode is used, allows remote authenticated users to cause a denial of service via a sequence of FTP sessions that include an invalid "NLST -1" command.
https://www.exploit-db.com/exploits/6717
https://exchange.xforce.ibmcloud.com/vulnerabilities/45806
http://www.vupen.com/english/advisories/2008/2801
http://www.securitytracker.com/id?1021040