Description
The worker's Netty message decoder is installed ahead of the SASL authentication handlers in the pipeline and acts on frames before any authentication has taken place. It allocated buffers sized from a length field carried in the frame, so a single frame from an unauthenticated peer able to reach a worker slot port could drive a large allocation.
storm.messaging.netty.authentication defaults to false, and the decoder runs before the handler that
enforces it in any case, so no credentials are required. The attacker needs only TCP reachability to a
worker port.
The effect of a single frame at the default 768 MB worker heap has not been measured to distinguish sustained worker loss from transient garbage-collection pressure. The severity assigned to this advisory reflects the more conservative reading; consumers who require a precise figure should test against their own worker heap configuration.
Mitigation
Upgrade to 3.1.0, where frames are decoded only after the handshake completes.
Users who cannot upgrade immediately should ensure that worker slot ports are reachable only from within the
cluster, as the security model already recommends, and should enable
storm.messaging.netty.authentication where the deployment permits it.
Credit
The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.