LLMs as hackers: Autonomous Linux privilege escalation attacks

Abstract

Penetration-testing is crucial for identifying and mitigating system vulnerabilities, with privilege-escalation being a critical subtask involving gaining elevated access to protected resources. The emergence of Large Language Models (LLMs) presents new avenues for automating these security practices by emulating human behavior. However, a comprehensive understanding of LLMs' efficacy and limitations in performing autonomous Linux privilege-escalation attacks remains underexplored. To address this gap, we introduce hackingBuddyGPT, a fully automated LLM-driven prototype designed for evaluating autonomous Linux privilege-escalation. We curated a novel, publicly available Linux privilege-escalation benchmark comprising distinct, single-vulnerability virtual machines, enabling controlled and reproducible evaluation. Our empirical analysis assesses the quantitative success rates and qualitative operational behaviors of various LLMs—GPT-3.5-Turbo, GPT-4-Turbo, and Llama3—against baselines of human professional penetration-testers and traditional automated tools. We investigate the impact of context management strategies, different context sizes, and various high-level guidance mechanisms on LLM performance. Results show that GPT-4-Turbo demonstrates high efficacy, successfully exploiting 33–83% of vulnerabilities, a performance comparable to human penetration testers (75%). In contrast, local models like Llama3 exhibited limited success (0–33%), and GPT-3.5-Turbo achieved moderate rates (16–50%). High-level guidance significantly boosts LLM success rates, for instance when using GPT-4-Turbo from 33% to 66% (without guidance) or from 66% to 83%, while state management through LLM-driven reflection doubled unaided GPT-4-Turbo success rates (from 33% to 66%). Qualitative analysis reveals both LLMs' strengths and weaknesses in generating valid commands and highlights challenges in common-sense reasoning, error handling, and multi-step exploitation, particularly with temporal dependencies. Cost analysis indicates that GPT-4-Turbo can achieve human-comparable performance at competitive costs per exploited vulnerability, especially with optimized context management. Our work provides a baseline for evaluating LLM capabilities in autonomous privilege escalation, guiding future research toward more effective and reliable LLM-guided penetration-testing.