can someone PUSH data to my socket connection?

I have web socket server(node.js) and the IOT(H/W) device which communicate over the internet using web socket.

I have steps for authentication and if both parties responds each other correctly then start data communication otherwise drop the connection.

Now, I am wondering that is that at all possible for some one to PUSH data on the socket which I am using as motioned above ?

This might not be a good question but I have to make sure that no harmful data push by hacker.

Any input,pointer or guide regarding the same is highly appreciated.

EDIT:

I am using ws:// , not a secure web socket as my H/W dose not support it for now.