Pre-Trained Model-Based Automated Software Vulnerability Repair: How Far are We?

Various approaches are proposed to help under-resourced security researchers to detect and analyze software vulnerabilities. It is still incredibly time-consuming and labor-intensive for security researchers to fix such reported vulnerabilities due to the increasing size and complexity of modern software systems. The time lag between the reporting and fixing of a security vulnerability causes software systems to suffer from significant exposure to possible attacks. Very recently, some techniques propose to apply pretrained models to fix security vulnerabilities and have proved their success in improving repair accuracy. However, the effectiveness of existing pre-trained models has not been systematically compared and little is known about their advantages and disadvantages. To bridge this gap, we perform the first extensive study on applying various pre-trained models to automated vulnerability repair. The experimental results on two vulnerability datasets show that all studied pre-trained models consistently outperform the state-ofthe- art technique VRepair with a prediction accuracy of 32.94
$\sim$
44.96%. We also investigate the impact of three major phases (i.e., data pre-processing, model training and repair inference) in the vulnerability repair workflow. Inspired by the findings, we construct a simplistic vulnerability repair approach that adopts the transfer learning from bug fixing. Surprisingly, such a simplistic approach can further improve the prediction accuracy of pre-trained models by 9.40% on average. Besides, we provide additional discussion from different aspects (e.g., code representation and a preliminary study with ChatGPT) to illustrate the capacity and limitation of pre-trained model-based techniques. Finally, we further pinpoint various practical guidelines (e.g., the improvement of fine-tuning) for advanced pre-trained model-based vulnerability repair in the near future. Our study highlights the promising future of adopting pre-trained models to patch real-world security vulnerabilities and reduce the manual debugging effort of security experts in practice.