Buffer overflows in WS_FTP 2.02 allow remote attackers to execute arbitrary code via long arguments to (1) DELE, (2) MDTM, (3) MLST, (4) MKD, (5) RMD, (6) RNFR, (7) RNTO, (8) SIZE, (9) STAT, (10) XMKD, or (11) XRMD.
https://exchange.xforce.ibmcloud.com/vulnerabilities/6911
http://www.ipswitch.com/Support/WS_FTP-Server/patch-upgrades.html