Any signed-in customer can read and change other customers’ invoices
How we reached it
- GET /api/invoices/10482signed in as customer B
- → 200 OKcustomer A’s invoice
- PATCH /api/invoices/10482amount changed to 1.00
- → 200 OK
What it means
Anyone with an account can see every customer’s names, addresses and amounts, and edit them.
Recommendation
Add an authorization check on the server: the invoice must belong to the signed-in account, on every read and write.