get_model(); if ( ! $model->sh_content_type_options ) { return false; } if ( isset( $model->sh_content_type_options_mode ) && 'nosniff' === $model->sh_content_type_options_mode ) { return true; } $headers = $this->head_request( network_site_url(), self::$rule_slug ); if ( is_wp_error( $headers ) ) { $this->log( sprintf( 'Self ping error: %s', $headers->get_error_message() ) ); return false; } if ( isset( $headers['x-content-type-options'] ) && is_null( $model->sh_content_type_options_mode ) ) { $model->sh_content_type_options_mode = 'nosniff'; $model->save(); return true; } return false; } /** * @return array */ public function get_misc_data() { $model = $this->get_model(); return array( 'intro_text' => esc_html__( 'The X-Content-Type-Options header is used to protect against MIME sniffing attacks. The most common example of this is when a website allows users to upload content to a website, however the user disguises a particular file type as something else.', 'wpdef' ), 'mode' => $model->sh_content_type_options_mode ?? 'nosniff', ); } public function add_hooks() { add_action( 'send_headers', array( $this, 'append_header' ) ); } public function append_header() { if ( headers_sent() ) { return; } $model = $this->get_model(); if ( ! $this->maybe_submit_header( 'X-Content-Type-Options', false ) ) { //this mean Defender can't override the already output, marked to show notification return; } if ( true === $model->sh_content_type_options && 'nosniff' === $model->sh_content_type_options_mode ) { header( 'X-Content-Type-Options: nosniff' ); } } /** * @return string */ public function get_title() { return __( 'X-Content-Type-Options', 'wpdef' ); } }