PHP auto-assigning query string variables without me doing anything

Question

I came across this when I realized I had a script that was working, but shouldn't be . I tested it by making a one line script as follows:

<?php
echo "<br>lang - $lang"; 
?>

When I run the script with query string ?lang=japanese it outputs:

lang - japanese

What the hell? No $_GET or $_REQUEST statements or anything but that one line. How is this happening???

Answer 1

Like Pekka said, it is likely you have register_globals turned on in your configuration. This is usually regarded as a security risk and should be turned off.

The feature itself was actually removed as of PHP 5.4.0