CoreWCF: Kafka consume pump halts permanently on a Kafka tombstone (null-value record), causing persistent endpoint denial of service.

Impact

A CoreWCF service is running and listening on a Kafka topic receiving a null-value record will stop processing new records from that topic.

Preconditions

The attacker has produce/write permission on a topic that CoreWCF is consuming from. If the broker permits anonymous publishes, no authentication is required.

Patches

Fixed in CoreWCF v1.8.1 and v1.9.1

Workarounds

Only allow authenticated writes to a topic