To mass / bulk update objects in Salesbox follow this flow

1. Go to the preferred section

2. Open the advanced search and either search to limit the list or not

3. Click the edit icon in the bottom right corner of advanced search and select mark all

4. Click the square data icon next to the Done button

5. Select what standard or custom field to update and add your value

6. Click done

All objects that was selected will now get that data value added.