Multiple cross-site scripting (XSS) vulnerabilities in @lex Guestbook 4.0.5 and earlier allow remote attackers to inject arbitrary web script or HTML via the (1) language_setup parameter to setup.php or (2) test parameter to index.php.  NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.  NOTE: a third party has been reported that the test parameter is not used in @lex Guestbook.