Risk of using $_SERVER['REQUEST_URI'] or $_SERVER['PHP_SELF'] in forms and links
<p>Is there any risk of using <code>$_SERVER['REQUEST_URI']</code> or <code>$_SERVER['PHP_SELF']</code> as the action in a form or as the href in a link?</p>

<p>If so, what can be done to alleviate the risk?</p>
