VPN Device ID Leaks: Are You At Risk?

TL;DR

Yes, VPNs that expose your device ID can be a security risk. While a VPN encrypts your internet traffic, leaking your device ID allows websites and trackers to identify you across different sessions and potentially link your activity back to you. This guide explains how this happens, the risks involved, and what you can do about it.

What is a Device ID?

A Device ID (like a fingerprint) uniquely identifies your computer, phone or tablet. It’s not the same as your IP address, but it’s often used alongside it for tracking purposes. Common IDs include:

• MAC Address: A unique identifier assigned to your network interface card.
• Hardware UUID: A unique number identifying specific hardware components.
• Browser Fingerprint: Information about your browser and system settings, combined to create a unique profile.

A good VPN should hide this information.

How Can a VPN Leak Device IDs?

Several things can cause leaks:

• Poorly Configured VPN Software: Some VPN apps don’t properly mask device identifiers.
• WebRTC Leaks: WebRTC (Web Real-Time Communication) is a technology used for video and audio calls in browsers. It can reveal your real IP address and sometimes other identifying information, even when using a VPN.
• Browser Settings & Extensions: Certain browser settings or extensions might expose device IDs regardless of the VPN.

What are the Risks?

1. Tracking Across Sessions: Websites can use your Device ID to recognise you even if your IP address changes frequently (e.g., when switching servers on a VPN).
2. Circumventing Geo-Restrictions: Some services block access based on device IDs, not just IPs. A leak could prevent the VPN from working as expected.
3. Fingerprinting: Combining your Device ID with other data creates a unique fingerprint that can be used to identify you even without cookies.
4. Privacy Concerns: Advertisers and trackers can build detailed profiles about your online activity based on your device.

How to Check for VPN Leaks

Several websites help test for leaks:

• BrowserLeaks: https://browserleaks.com/webrtc (for WebRTC)
• ipleak.net: https://ipleak.net/ (general leak test, including DNS and WebRTC)

Run these tests before and after connecting to your VPN.

Steps to Prevent Device ID Leaks

1. Choose a Reputable VPN: Select a well-known provider with a strong privacy policy. Read reviews and look for independent audits.
2. Enable Leak Protection: Most good VPN apps have built-in leak protection features (DNS, WebRTC). Make sure these are enabled in the settings.
   Example setting name might be ‘Prevent WebRTC Leaks’ or similar.
3. Disable WebRTC in Your Browser: If your VPN doesn’t block WebRTC effectively, disable it manually.
   • Chrome/Edge: Type chrome://flags/#disable-webrtc into the address bar and set ‘WebRTC non-proxy host override’ to your local IP address (e.g., 127.0.0.1). Restart your browser.
   • Firefox: Type about:config into the address bar, search for ‘media.peerconnection.enabled’, and set it to false. Restart Firefox.
4. Use Privacy-Focused Browsers: Consider browsers like Brave or Tor Browser which are designed with privacy in mind and often have built-in leak protection.
5. Disable JavaScript (with caution): JavaScript can be used to collect device information. Disabling it breaks many websites, so use this as a last resort.
   You can disable Javascript in your browser settings.
6. Regularly Check for Leaks: Periodically re-run the leak tests mentioned above to ensure your VPN is still protecting you.

Final Thoughts

A VPN is a valuable tool for improving your online privacy, but it’s not foolproof. Understanding and mitigating Device ID leaks is crucial for maximizing its effectiveness. Always verify that your VPN is working correctly and taking steps to protect your identity.