source: https://www.securityfocus.com/bid/2444/info
A remote user could gain read access to directories outside of the ftp root in a Jarle Aase War FTPD Server. Once a user is logged into the server, a specially crafted 'dir' command will disclose an arbitrary directory. This vulnerability could allow an attacker to gain read access to various files residing on the target machine.
dir *./../..