Advisory by Jose Carlos Norte
Wordpress is vulnerable to XSS attacks when custom 404 pages are used by the template.
The problem (sidebar.php):
<form method="get" id="searchform" action="<?php echo $_SERVER['PHP_SELF']; ?>">
if wordpress template use custom 404 pages, like:
<?php get_header(); ?>
<div id="content" class="narrowcolumn">
<h2 class="center">Error 404 - Not Found</h2>
</div>
<?php get_sidebar(); ?>
$_SERVER['PHP_SELF']; can contain special characters to break out html and perform XSS attacks, example:
http://www.example.com/index.php/";><script>alert(document.cookie)</script>
if no custom 404 page set by wordpress theme this attacks is not posible.
