WebRTC Leaks: How STUN Requests Expose Your Real IP Behind VPN

Browsers have WebRTC for real-time video/audio. To make P2P connections work, it needs to know your real physical IP address, bypassing proxies.

1. The STUN Server Trick

WebRTC sends a UDP packet to a STUN server asking: "What is my public IP?" This happens inside the browser engine, often ignoring the VPN tunnel.

Fix: Disable WebRTC in your browser config (media.peerconnection.enabled = false in Firefox).