WebRTC IP Leaks: How Local IPs Escape VPN Tunnels and How to Audit Them
Understanding ICE candidate discovery, STUN server queries, and browser defense mechanisms.
MindLucid Security Team
Core Network Architecture
Try It Live in Your Browser (Zero Server Upload)
Diagnostic requests are fetched directly from your browser to public endpoints.
Checks if local IP candidates are exposed to scripts via WebRTC ICE.
The Mechanism Behind WebRTC Leaks
WebRTC (Web Real-Time Communication) provides native browser video calling and data streaming. To connect two devices across different routers, WebRTC implements the ICE protocol to discover all available network paths:
- Local LAN IP addresses (e.g.,
192.168.1.xor10.x.x.x) - Public IP addresses derived via STUN queries
Why VPNs Often Fail Against WebRTC
Many commercial VPN clients only redirect standard TCP and UDP socket traffic at the operating system routing table. When a JavaScript script creates an RTCPeerConnection, the browser may query the default hardware interface directly, bypassing the virtual VPN adapter.
Audit Your Connection Live
Use the embedded inspector below to test your browser for WebRTC leaks in real time.
Frequently Asked Questions
What causes a WebRTC leak?
WebRTC uses Interactive Connectivity Establishment (ICE) to negotiate direct peer-to-peer audio/video feeds. To establish connections through NAT, it queries STUN servers, exposing real local and public IPs.
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