source: http://www.securityfocus.com/bid/6493/info

It has been reported that PlatinumFTPserver fails to properly sanitize some FTP commands. By sending a malicious request to the vulnerable server, using directory traversal sequences, it is possible for a remote attacker to delete sensitive resources located outside of the FTP root.

Deleting arbitrary files may render the system unusable. Other scenarios are also possible. 

delete ..\..\..\..\boot.ini