Is exposing SignalR connectionid a security risk

Question

I'm working on a chat app that's using signalr. I'm associating each user by their connectionid.

I'm just wondering if I broadcast all the users connectionids so anyone can see them in the code, would someone be able to cause any problems?

Answer 1

Sharing the connection ID is not a security risk as far as I know, sharing the connection token however is one.

From my own testing with SignalR it doesn't check the origin of a message but only the connection token, which is a encrypted form of the connection ID plus the username (if I remember correctly) if the session is authenticated (which is also why you need to reconnect after authenticating).

I was successfully able to spoof a SignalR connection from another computer on another IP with version 2.0.2 just by replacing the connection token.