source: http://www.securityfocus.com/bid/783/info

If an unusually long user name is passed to the Broker FTP server software, the program will crash. If the program is running as a service, the service will consume all available memory and crash the entire system. 

https://github.com/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/19611.zip