I'm always a worry-wart about security in my PHP applications, and I just (potentially) thought of a way a hacker could kill my script. Currently my application takes form data and submits it as an array to a PHP script via AJAX, then loops through this array.

foreach($_POST['form_data'] as $field => $value){ //Do something here. }

However, what if a hacker were to forge an AJAX request, and repeatedly submit the 'form_data' array with 100000000000 random elements? The loop would have to iterate through each element, possibly causing a DoS (or at least slow down service), correct?

I'm not entirely educated here, so I may have some incorrect assumptions. Thanks for any input!