Biblio

This paper deals with a problem that arises in vertical composition of protocols, i.e., when a channel protocol is used to encrypt and transport arbitrary data from an application protocol that uses the channel. Our work proves that we can verify that the channel protocol ensures its security goals independent of a particular application. More in detail, we build a general paradigm to express vertical composition of an application protocol and a channel protocol, and we give a transformation of the channel protocol where the application payload messages are replaced by abstract constants in a particular way that is feasible for standard automated verification tools. We prove that this transformation is sound for a large class of channel and application protocols. The requirements that channel and application have to satisfy for the vertical composition are all of an easy-to-check syntactic nature.

Industrial networks are the cornerstone of modern industrial control systems. Performing security checks of industrial communication processes helps detect unknown risks and vulnerabilities. Fuzz testing is a widely used method for performing security checks that takes advantage of automation. However, there is a big challenge to carry out security checks on industrial network due to the increasing variety and complexity of industrial communication protocols. In this case, existing approaches usually take a long time to model the protocol for generating test cases, which is labor-intensive and time-consuming. This becomes even worse when the target protocol is stateful. To help in addressing this problem, we employed a deep learning model to learn the structures of protocol frames and deal with the temporal features of stateful protocols. We propose a fuzzing framework named SeqFuzzer which automatically learns the protocol frame structures from communication traffic and generates fake but plausible messages as test cases. For proving the usability of our approach, we applied SeqFuzzer to widely-used Ethernet for Control Automation Technology (EtherCAT) devices and successfully detected several security vulnerabilities.