GHSA-v33r-r6h2-8wr7 Kimai's API invoice endpoint missing customer-level access control (IDOR)

• Packagist kimai/kimai: < 2.51.0 → fixed in 2.51.0

Summary `GET /api/invoices/{id}` only checks the role-based `view_invoice` permission but does not verify the requesting user has `access` to the invoice's customer. Any user with `ROLE_TEAMLEAD` (which grants `view_invoice`) can read all invoices in the system, including those belonging to customers assigned to other teams. Affected Code `src/API/InvoiceController.php` line 92-101: ```php [IsGranted('view_invoice')] // Role check only, no customer access check [Route(methods: ['GET'], path: '/{id}', name: 'get_invoice', requirements: ['id' => '\d+'])] public function getAction(Invoice $invoice): Response { $view = new View($invoice, 200); $view->getContext()->setGroups(self::GROUPS_ENTITY); return $this->viewHandler->handle($view); // Returns ANY invoice by ID } ``` The web controller (`src/Controller/InvoiceController.php` line 304-307) correctly checks customer access: ```php [IsGranted('view_invoice')] [IsGranted(new Expression("is_granted('access', subject.getCustomer())"), 'invoice')] public function downloadAction(Invoice $invoice, ...): Response { ... } ``` The `access` attribute in `CustomerVoter` (line 71-87) verifies team membership, but this check is entirely missing from the API endpoint. PoC Tested against Kimai v2.50.0 (Docker: `kimai/kimai2:apache`). Setup: • TeamA with CustomerA ("SecretCorp"), TeamB with CustomerB ("BobCorp") • Bob is a teamlead in TeamB only • An invoice exists for SecretCorp (TeamA) ```bash Bob (TeamB) reads SecretCorp (TeamA) invoice curl -H "Authorization: Bearer BOB_TOKEN" http://localhost:8888/api/invoices/1 ``` Response (200 OK): ```json { "invoiceNumber": "INV-2026-001", "total": 15000.0, "currency": "USD", "customer": {"name": "SecretCorp", ...} } ``` Bob can also enumerate all invoices via `GET /api/invoices` — the list endpoint uses `setCurrentUser()` in the query but the single-item endpoint bypasses this entirely via Symfony ParamConverter. Impact Any teamlead can read all invoices across the system regardless of team assignment. Invoice data typically contains sensitive financial information (amounts, customer details, payment terms). In multi-team deployments this breaks the intended data isolation between teams. Suggested Fix Add the customer access check to the API endpoint, matching the web controller: ```diff #[IsGranted('view_invoice')] +#[IsGranted(new Expression("is_granted('access', subject.getCustomer())"), 'invoice')] #[Route(methods: ['GET'], path: '/{id}', name: 'get_invoice')] public function getAction(Invoice $invoice): Response ```