This article is a collaboration between Joel Langill and Eric Byres. Joel is the CSO at SCADAhacker.com. He can be reached at joel@scadahacker.com.

In Part 1 of this series I explained what “state” means in network communications and the hazards of stateless security. Part 2 detailed the behavior of a stateless firewall and included a demonstration of me attacking one. In this closing article, I describe stateful inspection and its importance in securing ICS and SCADA systems. Read more »