This attack targets user controlled variables (DEBUG=1, PHP Globals, and
						So Forth). An attacker can override environment variables leveraging
						user-supplied, untrusted query variables directly used on the application
						server without any data sanitization. In extreme cases, the attacker can
						change variables controlling the business logic of the application. For
						instance, in languages like PHP, a number of poorly set default
						configurations may allow the user to override variables.