Scary Code Department

What could possibly go wrong with this snippet of PHP code from a
web-based CMS? Ignore the lack of error checking...

function publish_page($ID) {
       $page = $this->render($ID);
       $path = $this->div_path($page[1]);
       $file = $path.$page[2];
       # Write file
       $handle = fopen($file, "w");
       fwrite($handle, $page[0]);
       fclose($handle);
       chmod($file, 0666);
       $user = $this->auth->user;
       $this->db->q("update pages set published=now(), user='$user' where id='$ID'");
       return "$page[3] published...<br>";
}

Yup, it's a well-behaved CMS that publishes your files and makes
them world-writable.