CVE-2020-15222 Replay of private_key_jwt possible in ORY Fosite

In ORY Fosite (the security first OAuth2 & OpenID Connect framework for Go) before version 0.31.0, when using “private_key_jwt” authentication the uniqueness of the jti value is not checked. When using client authentication method “private_key_jwt”, OpenId specification says the following about assertion jti: “A unique identifier for the token, which can be used to prevent reuse of the token. These tokens MUST only be used once, unless conditions for reuse were negotiated between the parties”. Hydra does not seem to check the uniqueness of this jti value. This problem is fixed in version 0.31.0.