Threat modelling of industrial controllers: A firmware security perspective

Industrial devices are becoming more and more networked, as M2M communications gain acceptance. Industrial controllers are usually resource constrained real time devices, and the firmware of these controllers play a vital role enabling the controllers to function accurately and reliably. Binary image of the firmware in these embedded controllers are usually key intellectual property of any OEM making the device. Developing the firmware for a control function is a time consuming process, and being able to get the binary image of firmware can accelarate the product building for counterfieting. We provide a survey of the different threats, different attack methods to materialize the threats, attacker capability required to mount an attack based on an existing threat, and the impact of these attacks on the system. In this paper, we discuss the traditional industrial firmware management process like its distribution, updation and installation in industrial controllers, and describe the security threats in the firmware management methods. We also provide mitigation methods to the threats identified.