In this paper, we propose a novel networked control architecture capable of ensuring plant safety in the presence of cyber-attacks on the communication channels. First, by combining a coding scheme and a safety risk detection rule, an attack detection mechanism local to the plant is designed. Then, a set-theoretic controller is proposed as an emergency controller whenever an attack is detected and communication channels cannot be trusted. A numerical simulation involving a two-tanks water system is performed with the aim of clarifying the capabilities of the proposed solution.