    public function sdm_save_thumbnail_meta_data($post_id) {  // Save Thumbnail Upload metabox
	if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE)
	    return;
	if (!isset($_POST['sdm_thumbnail_box_nonce_check']) || !wp_verify_nonce($_POST['sdm_thumbnail_box_nonce_check'], 'sdm_thumbnail_box_nonce'))
	    return;

	if (isset($_POST['sdm_upload_thumbnail'])) {
	    update_post_meta($post_id, 'sdm_upload_thumbnail', $_POST['sdm_upload_thumbnail']);
	}
    }
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.