Looking for code inclusions?
The versatile google cluster has a solution for this, like for
many other tasks.
This search
lang:php \secho\([^)]*_REQUEST[^)]*\);
lets You find various places where some variable from the
superglobal $_REQUEST is printed with echo. By the same
means, you can easily find places where such a variable is
directly included in an SQL query, for instance with lang:php
\smysql_query\([^)]*_REQUEST[^)]*\); .
This alone yields 50 results for each query, but it may be varied
with printf() instead of echo() or just …