OpenAM: Unauthenticated Remote Code Execution via Class.forName in AuthXMLUtils.createCustomCallback

Open Access Management (OpenAM) is an access management solution. Prior to 16.1.2, the pre-authentication /authservice PLL endpoint accepts a CustomCallback XML element whose className value selects an arbitrary Java class for AuthXMLUtils to load and instantiate without verifying that it implements DSAMECallbackInterface. Default configurations expose the endpoint without authentication, allowing attacker-controlled class initialization and unsafe deserialization of a serialized Subject value to execute code in the server process. Enabling sunRemoteAuthSecurityEnabled does not prevent the vulnerable parsing and instantiation because its check occurs later. This issue is fixed in version 16.1.2.