Qiang Wei

Industrial control protocols (ICPs), especially proprietary protocols, lack public specifications due to security and commercial considerations, posing profound challenges for security audits and vulnerability detection. Although the function code fields in ICPs define critical operational semantics (e.g., PLC start/stop), existing protocol reverse engineering (PRE) methods struggle to accurately infer the functional implications of their value dependencies. To address this critical gap, we propose FuncSeinfer, an operation-traffic correlation-driven method for inferring functional semantics in proprietary ICPs by associating graphical user interface (GUI) operations of programming software with network traffic. FuncSeinfer first employs an entropy-based dynamic field extraction algorithm to generate candidate fields. Subsequently, it applies heuristic rules and clustering scoring rules to accurately infer function code fields. Finally, it identifies semantics through variance analysis of traffic marked with operational labels. We rigorously evaluated FuncSeinfer on 7 widely used ICPs (S7comm, UMAS-A, UMAS-B, Modbus, PCCC, Melsoft, and Fins) in 9 real-world PLCs from 5 leading manufacturers, achieving 100% accuracy in function code field inference, outperforming state-of-the-art PRE tools such as Netzob, FieldHunter, Netplier, and FSIBP. Furthermore, FuncSeinfer can accurately identify the semantic meaning of 78 function codes, which is an average improvement of 20.2% compared to Wireshark. This study fills the gap in functional semantics within ICP reverse engineering, enabling in-depth security analysis without requiring protocol specifications.

The persistent evolution of Internet of Things (IoT) devices across various sectors, including industrial applications, smart homes, and smart cities, has elevated the discourse surrounding the security of these devices to a pivotal status. Considering the pivotal role that IoT devices play when integrated into environments of grave import, such as manufacturing facilities and healthcare establishments, the potential for catastrophic consequences following a security breach is both profound and incalculable. It is, therefore, a matter of utmost priority to fortify the security protocols surrounding IoT devices. To effectively address the various security threats that confront IoT devices, a multi-dimensional investigative approach is mandated. This paper initiates with an elucidation of the research backdrop and a primer on the fundamental principles of IoT devices, then discusses the current state of IoT device security from two different dimensions: vulnerability detection and protective measures. Additionally, we forecast and discuss the research directions on vulnerability detection and protection measures for IoT devices.

Transient Execution Attacks (TEAs) have gradually become a major security threat to modern high-performance processors. They exploit the vulnerability of speculative execution to illegally access private data, and transmit them through timing-based covert channels. While new vulnerabilities are discovered continuously, the covert channels can be categorised to two types: 1) Persistent Type, in which covert channels are based on the layout changes of buffering, e.g. through caches or TLBs; 2) Volatile Type, in which covert channels are based on the contention of sharing resources, e.g. through execution units or issuing ports. The defenses against the persistent-type covert channels have been well addressed, while those for the volatile-type are still rather inadequate. Existing mitigation schemes for the volatile type such as Speculative Compression and Time-Division-Multiplexing will introduce significant overhead due to the need to stall the pipeline or to disallow resource sharing. In this paper, we look into such attacks and defenses with a new perspective, and propose a scheduling-based mitigation scheme, called SPECWANDS. It consists of three priority-based scheduling policies to prevent an attacker from transmitting the secret in different contention situations. SPECWANDS not only can defend against both inter-thread and intra-thread based attacks, but also can keep most of the performance benefit from speculative execution and resource-sharing. We evaluate its runtime overhead on SPEC 2017 benchmarks and realistic programs. The experimental results show that SPECWANDS has a significant performance advantage over the other two representative schemes.

Proprietary (or semi-proprietary) protocols are widely adopted in industrial control systems (ICSs). Inferring protocol format by reverse engineering is im

In an industrial cyber-physical system (iCPS), the controller plays a critical role in guaranteeing reliability and stability. Therefore, redundant controller architecture is a well-adopted approach by distributed control systems (DCS), supervisory control and data acquisition (SCADA), and other typical iCPSs. They monitor and control the critical industrial process, such as power generation, chemical industry, water treatment plant, etc. Redundant controller architecture has been designed and largely implemented in response to unpredictable mechanical failures. However, this structure initially proposed for guaranteeing reliability and safety may expand the cyber-attack surface, posing the risk that an attacker may take advantage of this architecture for stealthy attacks. In this article, we analyze the vulnerability arising from the redundant controller architecture and propose a combined attack methodology against these redundant controller architecture systems in a stealthy manner. We find several 0-day vulnerabilities of the real-world devices from three manufacturers and further implement the combined attack over these devices. Our experimental results over various types of real-world devices show that the redundant controller architecture can be exploited to compromise all tested systems stealthily. We also present guidelines for mitigating this risk.