In Apache Kafka versions between 0.11.0.0 and 2.1.0, it is possible to manually craft a Produce request which bypasses transaction/idempotent ACL validation. Only authenticated clients with Write permission on the respective topics are able to exploit this vulnerability. Users should upgrade to 2.1.1 or later where this vulnerability has been fixed.

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.

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.