whatsapp-api-js fails to validate message's signature

whatsapp-api-js is a TypeScript server agnostic Whatsapp's Official API framework. It's possible to check the payload validation using the WhatsAppAPI.verifyRequestSignature and expect false when the signature is valid. Incorrect Access Control, anyone using the post or verifyRequestSignature methods to handle messages is impacted. This vulnerability is fixed in 4.0.3.