Ory Kratos is an identity, user management and authentication system for cloud services. Prior to version 1.3.0, given a number of preconditions, the highest_available setting will incorrectly assume that the identity’s highest available AAL is aal1 even though it really is aal2. This means that the highest_available configuration will act as if the user has only one factor set up, for that particular user. This means that they can call the settings and whoami endpoint without a aal2 session, even though that should be disallowed. An attacker would need to steal or guess a valid login OTP of a user who has only OTP for login enabled and who has an incorrect available_aal value stored, to exploit this vulnerability. All other aspects of the session (e.g. the session’s aal) are not impacted by this issue. On the Ory Network, only 0.00066% of registered users were affected by this issue, and most of those users appeared to be test users. Their respective AAL values have since been updated and they are no longer vulnerable to this attack. Version 1.3.0 is not affected by this issue. As a workaround, those who require MFA should disable the passwordless code login method. If that is not possible, check the sessions aal to identify if the user has aal1 or aal2.
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.