Vulnerability analysis of a PLC via Modbus TCP and MELSOFT protocols

The cybersecurity of operational technology (OT) environments is crucial because manufacturing has become the most cyber-attacked industry. In the past, many research efforts focused on the information technology (IT) environment instead of the OT environment, so it is time for us to thoroughly investigate the cybersecurity of general OT environments. Programmable logic controllers (PLCs) are fundamental in OT environments, but often lack sufficient cybersecurity safeguards. The objective of a research was to perform the vulnerability assessment of a popular PLC, particularly examining its use of the Modbus TCP protocol and MELSOFT protocol. Using the vulnerability testing, we evaluated the security risks associated with this device. On the basis of these results, mitigation strategies for industrial network hardening are proposed to enhance resilience against cyber threats.