Secure access to databases

I am using the Table JX with some restricted access data displaying the grids as plugins on restricted access pages.

But I have found that it is possible to access all grids by using a joomla query like .../?option=com_grid&gid=2. In this way all databases covered by those grids are available without any password.

There is a way to secure this access?

The access to the database is closed by this additional condition, thank you.

You can still find an access to the component by adding ?option=com_grid&gid= but the returned database is empty.