Analysis of Security Findings and Reduction of False Positives through Large Language Models
Year: 2024
Type: dissertation
Abstract: This thesis investigates the integration of State-of-the-Art (SOTA) Large Language Models (LLMs) into the process of reassessing security findings generated by Static Application Security Testing (SAST) tools. The primary objective is to determine whether LLMs are able to detect false positives (FPs) while maintaining a high true positive (TP) rate, thereby enhancing the efficiency and effectiveness of security assessments. Four consecutive experiments were conducted, each addressing specific research questions. The initial experiment, using a dataset of security findings extracted from the OWASP Bench- mark, identified the optimal combination of context items provided by the SAST tool Spot- Bugs, which, when used with GPT-3.5 Turbo, reduced FPs while minimizing the loss of TPs. The second experiment, conducted on the same dataset, demonstrated that advanced prompting techniques, particularly few-shot Chain-of-Thought (CoT) prompting combined with Self-Consistency (SC), further improved the reassessment process. The third experiment compared both proprietary and open-source LLMs on an OWASP Benchmark dataset about one-fourth the size of the previously used dataset. GPT-4o achieved the highest performance, detecting 80 out of 128 FPs without missing any TPs, resulting in a perfect TPR of 100% and a decrease in FPR by 41.27 percentage points. Meanwhile, Llama 3.1 70B detected 112 out of the 128 FPs but missed 10 TPs, resulting in a TPR of 94.94% and a reduction in FPR by 56.62 percentage points. To validate these findings in a real-world context, the approach was applied to a dataset generated from the open-source project Mnestix using multiple SAST tools. GPT-4o again emerged as the top performer, detecting 26 out of 68 FPs while only missing one TP, resulting in a TPR decreased by 2.22 percentage points but simultaneously an FPR decreased 37.57 percentage points.:Table of Contents IV List of Figures VI List of Tables VIII List of Source Codes IX List of Abbreviations XI 1. Motivation 1 2. Background 3 3. Related Work 17 4. Concept 31 5. Preparing a Security Findings Dataset 39 6. Implementing a Workflow 51 7. Identifying Context Items 67 8. Comparing Prompting Techniques 85 9. Comparing Large Language Models 101 10.Evaluating Developed Approach 127 11.Discussion 141 12.Conclusion 145 A. Appendix: Figures 147 A.1. Repository Directory Tree 148 A.2. Precision-Recall Curve of Compared Large Language Models 149 A.3. Performance Metrics Self-Consistency on Mnestix Dataset 150 B. Appendix: Tables 151 B.1. Design Science Research Concept 151 C. Appendix: Code 153 C.1. Pydantic Base Config Documentation 153 C.2. Pydantic LLM Client Config Documentation 155 C.3. LLM BaseClient Class 157 C.4. Test Cases Removed From Dataset 158
Author: Wagner, Jonas
Language: English
Subfield: Information Systems
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W6989291498