add_action('send_headers', function(){ // Prevent Clickjacking header("X-Frame-Options: SAMEORIGIN"); // Prevent XSS Attack header("Content-Security-Policy: default-src 'self';"); // FF 23+ Chrome 25+ Safari 7+ Opera 19+ header("X-Content-Security-Policy: default-src 'self';"); // IE 10+ // Block Access If XSS Attack Is Suspected header("X-XSS-Protection: 1; mode=block"); // Prevent MIME-Type Sniffing header("X-Content-Type-Options: nosniff"); // Referrer Policy header("Referrer-Policy: no-referrer-when-downgrade"); }, 1);