»Hacking attempt?«

Sometimes a hacker may try to alter variables of PHP, for example by calling "viewtopic.php?GLOBALS[...]".
Sometimes a hacker tries to cause errors by sending data that is very long (e.g. a username that is 10 megabyte characters long).
These are clear hacking attempts and we can filter them out by the following code:• Open "common.php"
• Find if ( !defined('IN_PHPBB') )

{
    die('Hacking attempt');
} 

Insert thereafter:
foreach ($_REQUEST as $varname => $value)
{
if (
(preg_match('#^(globals|_|http_|php_|argv|knnvalues|argc|gateway_|server_|request_|query_|document_|remote_|script_|path_|auth_)#i',$varname)) // If someone tries to do some hacking tricks
|| (strlen($value) >= 1*1024*1024) // If posting is too long (> 1 MB)
)
{
die('Hacking attempt');
}
}


What does this code do? It finds out whether someone tries to influence global variables like $GLOBALS or $HTTP_POST_VARS and if so, then it stops.

I have not tested it out completely with all functions of phpbb and all mods, but since it works on my heavy modded site it should work on yours too