Directory traversal vulnerability in SunFTP build 9 allows remote attackers to read arbitrary files via .. (dot dot) characters in various commands, including (1) GET, (2) MKDIR, (3) RMDIR, (4) RENAME, or (5) PUT.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2001-0283
http://archives.neohapsis.com/archives/bugtraq/2001-02/0523.html