Directory traversal vulnerability in ftpd in QPC QVT/Net 4.0 and AVT/Term 5.0 allows a remote attacker to traverse directories on the web server via a "dot dot" attack in a LIST (ls) command.
https://exchange.xforce.ibmcloud.com/vulnerabilities/6375
https://euvd.enisa.europa.eu/vulnerability/EUVD-2001-0666
http://www.securityfocus.com/bid/2618