Wheels on the Modbus - Attacking ModbusTCP Communications

Abstract

Industrial Cyber-Physical Systems (ICPS) make significant use of Supervisory Control and Data Acquisition (SCADA) for control. Such SCADA systems are known to utilise insecure communication protocols such as Modbus, DNP3 and OPC DA. This leads to increased cyber risks faced in critical infrastructures, as these protocols allow threat actors to mount attacks like Denial of Service (DoS). We present a novel field flooding attack, compromising the structure of the ModbusTCP packet and disrupting a controller's interpretation of the commands sent to it. This can disrupt the ability of an operator to control hazardous operations leading to potentially unsafe scenarios.