Core FTP LE version 2.2 Build 1921 is prone to a buffer overflow vulnerability that may result in a DoS or remote code execution via a PASV response.
https://gist.github.com/berkgoksel/e97b3f3b15e2f8293f649d4ebe6a6fc9
https://gist.github.com/berkgoksel/a654c8cb661c7a27a3f763dee92016aa
http://packetstormsecurity.com/files/148383/Core-FTP-LE-2.2-Buffer-Overflow.html