CompactLogix unauthenticated firmware overwrite

A flaw in the firmware update routine allows unauthenticated attackers on the local subnet to overwrite controller firmware over CIP, leading to denial of process and remote code execution.

Mitigations

01Upgrade to firmware ≥ 33.012
02Restrict CIP traffic to engineering workstations only
03Place controllers in a Level 1 zone with a single conduit to Level 2