Smart seed selection-based effective black box fuzzing for IIoT protocol

Connections of cyber-physical system (CPS) components are gradually increasing owing to the introduction of the Industrial Internet of Things (IIoT). IIoT vulnerability analysis has become a major issue because complex skillful cyber-attacks on CPS systems exploit their zero-day vulnerabilities. However, current white box techniques for vulnerability analysis are difficult to use in real heterogeneous environments, where devices supplied by various manufacturers and diverse firmware versions are used. Therefore, we herein propose a novel protocol fuzzing test technique that can be applied in a heterogeneous environment. As seed configuration can significantly influence the test result in a black box test, we update the seed pool using test cases that travel different program paths compared to the seed. The input, output, and Delta times are used to determine if a new program area has been searched in the black box environment. We experimentally verified the effectiveness of the proposed.