Directory traversal vulnerability in the FTP server in Serv-U 7.0.0.1 through 7.3, including 7.2.0.1, allows remote authenticated users to overwrite or create arbitrary files via a ..\ (dot dot backslash) in the RNTO command.
https://www.exploit-db.com/exploits/6661
http://www.vupen.com/english/advisories/2008/2746