Mailchimp for WooCommerce < 6.3 - Unauthenticated Customer Email and Cart Disclosure via IDOR

The Mailchimp for WooCommerce WordPress plugin before 6.3 does not require authentication or verify ownership before loading a saved cart from a request-supplied identifier that is derived from a customer's email address, allowing an unauthenticated attacker who knows a customer's email address to confirm that the customer shops at the store and to read that customer's saved cart contents.