Spree: Broken Access Control in `PATCH /api/v3/store/carts/:id/associate` (IDOR)

Summary The Store API v3 endpoint PATCH /api/v3/store/carts/:id/associate binds a guest cart to the authenticated caller without verifying possession of that cart. It locates the cart by prefixed ID only — currentstore.carts.whereuser: nil, currentuser.findbyprefixid!params:id — and omits the...