Stockholm International Summit on Cyber Security in SCADA and Industrial Control Systems

Description

PLCs are playing a major role in critical infrastructures. Similar to other computer systems PLCs are vulnerable to code-reuse attacks. Compromising these devices in a critical environment constitute a significant security and safety risk.

Code-reuse mitigations previously suggested for general-purpose computers. However, there are specific PLC specific constraints that were never addressed in other code-reuse mitigation systems in general-purpose computers.

Firstly, PLCs are embedded systems that are extremely heterogeneous concerning the processing power. Secondly, the PLC vendors tend to procure third party software only available in Commercial Off-The-Shelf (COTS) binary form. Finally, one cannot rely on the presence of any particular hardware, hardware-facilitated functionality or hardware-specific features for a memory corruption mitigation approach in the PLCs.

In this presentation, we introduce an open source code-reuse mitigation system for PLC binaries. Our system addresses the performance diversity (the first constraint) of the PLCs by providing configurable protection policies, that can be tailored to the specific system. Also, our system protects COTS binaries (second constraint) without relying on the control-flow graph and can work with hardware-agnostic cryptographically secure shadow stack.

To the best of our knowledge, no memory corruption mitigation approach for embedded systems in general and specifically for the PLCs, addresses all limitations mentioned above.

For evaluation of our work, we choose ARM since it is a common architecture in the PLCs. Our evaluation shows that our code-reuse mitigation system provides its protection with a limited performance overhead for COTS binaries of the PLC.

Period	20 Oct 2017
Event type	Conference
Location	Stockholm, Sweden
Degree of Recognition	International