X-Diesel Unreal Commander 0.92 build 565 and 573 does not properly react to an FTP server's behavior after sending a "CWD /" command, which allows remote FTP servers to cause a denial of service (infinite loop) by (1) repeatedly sending a 550 error response, or (2) sending a 550 error response and then disconnecting.
https://exchange.xforce.ibmcloud.com/vulnerabilities/36488
http://www.securityfocus.com/archive/1/478728/100/0/threaded