A vulnerability detection framework by focusing on critical execution paths

Vulnerability detection is critical to ensure software security, and detecting vulnerabilities in smart contract code is currently gaining massive attention. Existing deep learning-based vulnerability detection methods represent the code as a code structure graph and eliminate vulnerability-irrelevant nodes. Then, they learn vulnerability-related code features from the simplified graph for vulnerability detection. However, this simplified graph struggles to represent relatively complete structural information of code, which may affect the performance of existing vulnerability detection methods. In this paper, we present a novel Vulnerability Detection framework based on Critical Execution Paths (VDCEP), which aims to improve smart contract vulnerability detection. Firstly, given a code structure graph, we deconstruct it into multiple execution paths that reflect rich structural information of code. To reduce irrelevant code information, a path selection strategy is employed to identify critical execution paths that may contain vulnerable code information. Secondly, a feature extraction module is adopted to learn feature representations of critical paths. Finally, we feed all path feature representations into a classifier for vulnerability detection. Also, the feature weights of paths are provided to measure their importance in vulnerability detection. We evaluate VDCEP on a large dataset with four types of smart contract vulnerabilities. Results show that VDCEP outperforms 14 representative vulnerability detection methods by 5.34%–60.88% in F1-score. The ablation studies analyze the effects of our path selection strategy and feature extraction module on VDCEP. Moreover, VDCEP still outperforms ChatGPT by 34.46% in F1-score. Compared to existing vulnerability detection methods, VDCEP is more effective in detecting smart contract vulnerabilities by utilizing critical execution paths. Besides, we can provide interpretable details about vulnerability detection by analyzing the path feature weights.