The login mechanism via device authentication of CGFIDO from Changing Information Technology has an Authentication Bypass vulnerability. If a user visits a forged website, the agent program deployed on their device will send an authentication signature to the website. An unauthenticated remote attacker who obtains this signature can use it to log into the system with any device.
A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).