OpenAM Pre-auth RCE via Java Deserialization in WebAuthn Authenticator Storage

Open Access Management (OpenAM) is an access management solution. Prior to 16.1.1, WebAuthnAuthentication loads a serialized AuthenticatorImpl object graph from the configured userAttribute through loadAuthenticators without an ObjectInputFilter. Exploitation requires the WebAuthn flow to be reachable and an attacker to have previously written controlled data to that attribute through delegated administration, provisioning, directory access, legacy REST self-registration, or unsafe configuration. When those non-default conditions hold, the data is deserialized before assertion verification and can execute a classpath gadget in the application server process. This issue is fixed in version 16.1.1.