Cursor IDE Security Best Practices & Tips

Cursor (also called Cursor AI) is an AI-powered code editor / IDE that deeply integrates generative models (e.g. OpenAI, Claude, Gemini) with knowledge of your codebase to assist in writing, refactoring, debugging, and navigating code. Its main benefits include dramatically reduced boilerplate work, context-aware multi-file edits, natural language interaction with code, smarter predictive edits, and built-in privacy modes for security. 

Cursor has seen rapid growth: its parent company Anysphere recently raised $900 million, valuing it around $9 billion, and some reports suggest Cursor reached a staggering ~1 million users (360,000 paying) within 16 months of launch.

Understanding the Threat Model Around Cursor

Cursor is more than just an IDE — it’s an AI coding environment that can execute commands, edit files, and interact with external tools on your machine. These extensive capabilities can introduce many new risks if not properly governed and defended:

• Command Injection via AI suggestions: malicious prompts or poisoned training data could trick rm -rf /, curl to exfiltrate data.
• Data Exfiltration: AI agents could read sensitive files (API keys, dotfiles, configs) and leak them.
• Persistence & System Modification: AI may alter hidden configuration files or install software for persistence, or hide malicious code in dotfiles that keep re-running after restarts.
• Bypassing Safeguards: built-in protections are not foolproof and may be sidestepped with carefully crafted commands. In a previous blog, we showed how Cursor’s auto-run mode Denylist feature was pretty much useless against simple manipulation. As a result of our findings, Cursor completely removed this feature and it’s currently not available.
  

Key Security Configuration Settings

All security-relevant settings are stored in: ~/Library/Application/Support/Cursor/User/globalStorage/state.vscdb

Alternatively, they can be controlled from the UI, where developers can by mistake allow settings that can put them in danger.

The following are the important configurations and their recommended settings:

Best Practices for Secure Configuration of Cursor

To minimize risk, we recommend the following setup:

1. Turn OFF Auto Run Mode – always review commands before execution. If you must allow it, use Allow Lists and other protections.
2. Enable Allow List Mode, but keep the list minimal – avoid adding commands that can escalate into destructive actions (e.g., rm, curl, find).
3. Keep File Deletion and Dotfile Protection ON – even if not bulletproof, they add friction against accidental or malicious actions.
4. Do not rely on External File Protection – assume it’s ineffective. Use OS-level controls instead.
5. Always enable MCP Tool Protection – prevents external AI tools from running unchecked.
6. Manually review AI-suggested commands – never trust blindly, especially ones involving file writes, system paths, or networking.
7. Use version control aggressively – ensure every project is in git (or similar) so any AI-triggered change can be rolled back.
8. Restrict terminal usage – prefer running commands in a sandboxed or containerized environment when possible.

What’s Missing – External Security Measures

Like every product’s internal security features, Cursor’s built-in security settings are a good start but leave some gaps that must be addressed using additional layers of security:

• OS Permissions & Sandboxing: Run Cursor inside a restricted user account or container (Docker, Podman, VM). Don’t give it root privileges.
• Filesystem Protections: Use tools like AppArmor or macOS sandboxing to prevent the IDE from touching sensitive directories (~/.ssh/, ~/Secrets/).
• Network Controls: Cursor doesn’t restrict outbound connections. Use firewalls or proxies to limit data exfiltration risk.
• Secrets Management: Keep API keys and credentials out of plain files, and don’t hard-code them. Store them in a vault (e.g., HashiCorp Vault, AWS Secrets Manager) where they can get proper protection and be rotated/revoked as needed.
• Dependency Hygiene: Don’t let AI auto-install packages without review. Package install scripts can be trojanized.
• Audit & Monitoring: Regularly audit your ~/Library/Application Support/Cursor/ directory and project repositories for suspicious changes.

FAQs on Secure Cursor Use

1. How can auto-run commands be safely managed in Cursor?
   Auto-run (formerly known as YOLO mode) commands should be disabled or heavily restricted to prevent Cursor from executing unauthorized actions or malicious code without a developer’s review.
2. What is Privacy Mode and when should it be enabled?
   Privacy Mode ensures that code and interactions are never stored by model providers or used for training, protecting proprietary logic and sensitive information. It should be enabled in the Cursor Settings for projects handling confidential data or where code IP is sensitive.
3. How can prompt injection risks be reduced?
   Review and validate all prompt and rules file inputs before use, and sanitize developer context windows by removing sensitive code fragments, credentials, and proprietary business logic to mitigate prompt injection attacks.
4. What steps secure dependencies managed through Cursor?
   Always vet NPM (or other) packages before execution—check the package sources, maintainers, and update histories. Prefer well-maintained packages and regularly scan for known vulnerabilities to prevent supply chain attacks.
5. What’s important for credential and secret management in Cursor projects?
   Strictly avoid hardcoding secrets, API keys, and passwords in source code. Use dedicated secret management tools (like Secretlint, AWS Secret Manager, or similar) and scan repositories for secrets prior to import or commit.

Conclusion: Vibe Safely

Cursor IDE is a game-changer. It empowers developers with AI superpowers, but it blurs the line between assistant and insider threat. Misconfigured, it could delete your files, leak your secrets, or persist malicious changes.

To mitigate these risks, be sure to have:

1. Proper configuration inside Cursor (turning off risky modes, enabling strong protections)
2. External defenses at the OS, network, and workflow level.
3. Always treat AI commands as you would treat untrusted code.
   

By following these practices, developers and security teams can safely harness Cursor’s productivity boost — without handing attackers the keys to their workstations and code.

References:

1. Cursor docs - Cursor ai documentation
2. Cursor Security: Key Risks, Protections & Best Practices - Reco
3. How To Use Cursor AI: A Complete Guide With Practical Examples
4. Cursor AI Security - Deep Dive into Risk, Policy, and Practice
5. Secure and Smart Practices for Using Cursor AI