This host is running pyftpdlib FTP server and is prone to Denial of Service vulnerability.
Successful exploitation will allow attacker to cause a denial of service. Impact Level: Application
Upgrade to pyftpdlib version 0.5.2 or later, For updates refer to http://code.google.com/p/pyftpdlib/downloads/list
The flaw is due to race condition in the FTPHandler class, which allows remote attackers to cause a denial of service by establishing and then immediately closing a TCP connection, leading to the accept function having an unexpected return value of None.
ftpserver.py in pyftpdlib before 0.5.1