Multiple cross-site scripting (XSS) vulnerabilities in Joomla! before 1.6.4 allow remote attackers to inject arbitrary web script or HTML via (1) the query string to the com_contact component, as demonstrated by the Itemid parameter to index.php; (2) the query string to the com_content component, as demonstrated by the filter_order parameter to index.php; (3) the query string to the com_newsfeeds component, as demonstrated by an arbitrary parameter to index.php; or (4) the option parameter in a reset.request action to index.php; and, when Internet Explorer or Konqueror is used, (5) allow remote attackers to inject arbitrary web script or HTML via the searchword parameter in a search action to index.php in the com_search component.