Membership For WooCommerce < 3.1.2 - Unauthenticated Member Data Disclosure via REST Consumer Secret Bypass

The Membership For WooCommerce WordPress plugin before 3.1.2 does not check that an API consumer secret has actually been generated before comparing it against the one supplied in a request, allowing unauthenticated attackers to reach its REST routes and disclose any user's membership plan details on sites where the API has been enabled but no keys were ever generated.