Directory traversal vulnerability in Advanced Guestbook 2.4.2 allows remote attackers to bypass .htaccess settings, and execute arbitrary PHP local files or…

Directory traversal vulnerability in Advanced Guestbook 2.4.2 allows remote attackers to bypass .htaccess settings, and execute arbitrary PHP local files or read arbitrary local templates, via a .. (dot dot) in a lang cookie, followed by a filename without its .php extension, as demonstrated via a request to index.php.