Detecting Code Vulnerabilities using LLMs
Larry K. Huynh, Yinghao Zhang, Djimon Jayasundera, Woojin Jeon, Hyoungshick Kim, Tingting Bi, Jin B. Hong · 2025
Large language models (LLMs) have emerged as a promising tool for detecting code vulnerabilities, potentially offering advantages over traditional rule-based methods. This paper proposes an enhanced framework for vulnerability detection using LLMs, incorporating various prompt engineering strategies to improve performance. We evaluate several techniques, including role-based prompting, zero-shot chain-of-thought, and structured prompting approaches, on the DiverseVul dataset of C/C++ vulnerabilities. Our experiments assess the framework’s performance across different code structures, contextual information levels, and LLM capabilities. Our results show that using our dynamic prompt engineering technique, you can improve the F1 score by up to 100% with GPT-3.5, a widely used LLM model. We also observe that GPT-4o, Gemini 2.0 Flash, and Meta Llama 3.1 generally outperform GPT-3.5, and all models are very poor when it comes to correctly identifying the type of vulnerability in the code, with the best F1 score of 0.16 observed. However, our follow-up experiments on LLM-based vulnerability correction (i.e., patching) show a 45.77% success rate using GPT-4o, demonstrating promising results in leveraging LLMs for enhancing software security and providing insights into optimizing prompt engineering for vulnerability detection tasks.