public static function vulnerable()
 {
     $slim = Slim::getInstance();
     if ($slim->request->isGet()) {
         $id = $slim->request->params("id");
         try {
             $compras = Compras::vulnerable_buscar_por_id($id);
             die(json_encode($compras));
         } catch (Exception $ex) {
             die($ex->getMessage());
         }
     }
 }