In Apache Kafka 0.10.0.0 to 0.10.2.1 and 0.11.0.0 to 0.11.0.1, authenticated Kafka clients may use impersonation via a manually crafted protocol message with SASL/PLAIN or SASL/SCRAM authentication when using the built-in PLAIN or SCRAM server implementations in Apache Kafka.
In Apache Kafka 0.9.0.0 to 0.9.0.1, 0.10.0.0 to 0.10.2.1, 0.11.0.0 to 0.11.0.2, and 1.0.0, authenticated Kafka users may perform action reserved for the Broker via a manually created fetch request interfering with data replication, resulting in data loss.