Joomla Extension - j2commerce.com - Guest checkout address disclosure to any authenticated user (IDOR) in J2Store 1.0.0-3.3.21, 4.0.0-4.0.21, 4.1.0-4.1.6 - `editAddress()` redirected non-owners away only when the loaded address row had a **non-empty** `user_id` belonging to someone else. Guest-checkout address rows have an empty `user_id`, so that check never triggered for them — any logged-in account guessing a small, sequential `address_id` got a guest customer's full name, street address, and phone number rendered prefilled into the edit form.