Mitm Attack on WebRtc

Question

I have a problem. I developed a web application using WebRtc for individual video calls through a browser using WebRtc with a signaling server on node js (listening, for example, on port 8181).

Now I would do a MITM attack. I thought wheer Peer_1 should call two rtc peers, one for the second peer (Peer_2), one for MITM. The same goes for the second partner.

Now I thought that the signaling server should listen on a different port, for each rtc peer connection received from two peers (for example, 8282 for Peer_1 and 8383 for Peer_2).

I'm right? I think that since the signaling server implementation is an individual message.

Thus, the signaling server on port 8181 provides end-to-end communication for Peer_1 and Peer_2, and on 8282, the signaling path for Peer_1 and MITM, and 8383 for MITM and Peer_2.

Am I right or not? Thanks for the support.

Answer 1

The man in the middle refers to interception during transmission, which WebRTC itself is protected from using DTLS and key exchange, so the weak point is usually the signaling server selected by the application.

But what you are describing seems to be Human from both ends. You must trust the service (server) to guarantee who you are connected to. If this server is hacked or the client is compromised - say, by injection - then there is no guarantee who you are talking to, because the client can easily forward the transfer to the other side.