Multiple cross-site request forgery (CSRF) vulnerabilities in the Private Only plugin 3.5.1 for WordPress allow remote attackers to hijack the authentication of administrators for requests that (1) add users, (2) delete posts, or (3) modify PHP files via unspecified vectors, or (4) conduct cross-site scripting (XSS) attacks via the po_logo parameter in the privateonly.php page to wp-admin/options-general.php.