Identifying Helpful Context for LLM-based Vulnerability Repair: A Preliminary Study

Recent advancements in large language models (LLMs) have shown promise for automated vulnerability detection and repair in software systems. This paper investigates the performance of GPT-4o in repairing Java vulnerabilities from a widely used dataset (Vul4J), exploring how different contextual information affects automated vulnerability repair (AVR) capabilities. We compare the latest GPT-4o's performance against previous results with GPT-4 using identical prompts. We evaluated nine additional prompts crafted by us that contain various contextual information such as CWE or CVE information, and manually extracted code contexts. Each prompt was executed three times on 42 vulnerabilities, and the resulting fix candidates were validated using Vul4J's automated testing framework. Our results show that GPT-4o performed 11.9\% worse on average than GPT-4 with the same prompt, but was able to fix 10.5\% more distinct vulnerabilities in the three runs together. CVE information significantly improved repair rates, while the length of the task description had minimal impact. Combining CVE guidance with manually extracted code context resulted in the best performance. Using our \textsc{Top}-3 prompts together, GPT-4o repaired 26 (62\%) vulnerabilities at least once, outperforming both the original baseline (40\%) and its reproduction (45\%), suggesting that ensemble prompt strategies could improve vulnerability repair in zero-shot settings.