Originally Posted by fluffygrrl

It's not really a vulnerability per se.

Upon installing a new template, you grant code in there same rights as the wp package. An infected template then alters the p_footer() hook, wp_head() hook or both, ads some entries in a bogus wp_options entrace in the options table, and voila. You're infected.

Moral is, never install code you haven't read. Don't be shy to crack "protected" stuff, especially if it's widgets, templates and the like.