Secure and Efficient Access Control for Computer-Use Agents via Context Space
Haochen Gong , Chenxiao Li , Rui Chang , Wenbo Shen
Published on arXiv
2509.22256
Excessive Agency
OWASP LLM Top 10 — LLM08
Prompt Injection
OWASP LLM Top 10 — LLM01
Key Finding
CSAgent successfully defends against all attacks in the evaluation benchmarks while introducing only 1.99% performance overhead and 5.42% utility decrease across GUI, API, and CLI interfaces.
CSAgent
Novel technique introduced
Large language model (LLM)-based computer-use agents represent a convergence of AI and OS capabilities, enabling natural language to control system- and application-level functions. However, due to LLMs' inherent uncertainty issues, granting agents control over computers poses significant security risks. When agent actions deviate from user intentions, they can cause irreversible consequences. Existing mitigation approaches, such as user confirmation and LLM-based dynamic action validation, still suffer from limitations in usability, security, and performance. To address these challenges, we propose CSAgent, a system-level, static policy-based access control framework for computer-use agents. To bridge the gap between static policy and dynamic context and user intent, CSAgent introduces intent- and context-aware policies, and provides an automated toolchain to assist developers in constructing and refining them. CSAgent enforces these policies through an optimized OS service, ensuring that agent actions can only be executed under specific user intents and contexts. CSAgent supports protecting agents that control computers through diverse interfaces, including API, CLI, and GUI. We implement and evaluate CSAgent, which successfully defends against all attacks in the benchmarks while introducing only 1.99% performance overhead and 5.42% utility decrease.
Key Contributions
- Intent- and context-aware static policy specification (context space) that bridges the gap between fixed developer-authored rules and dynamic user intent at runtime
- Automated LLM-based policy generation toolchain that assists developers in constructing context spaces for API-, CLI-, and GUI-based agents
- Optimized OS service enforcing the policies at runtime with only 1.99% performance overhead and 5.42% utility decrease while blocking all benchmark attacks