Search Unity

  1. Megacity Metro Demo now available. Download now.
    Dismiss Notice
  2. Unity support for visionOS is now available. Learn more in our blog post.
    Dismiss Notice

Third Party Mirror - Receiving negative sized header attacks?

Discussion in 'Multiplayer' started by ToastSub, May 22, 2023.

  1. ToastSub

    ToastSub

    Joined:
    Apr 8, 2023
    Posts:
    2
    I have no idea what caused this. Through process of elimination of disabling things I don't think it's anything my scripts did. At first I kept getting this in my console when I started as server as either server or host:
    ReceiveLoop: finished receive function for connectionId=1 reason: System.OverflowException

    I would keep getting this as it iterated through connectionIds and I couldn't connect to myself as a client. After messing around with stuff trying to figured out the problem I tried uninstalling and reinstalling Mirror. This caused the error it would spam to change to this:
    [Telepathy] ReadMessageBlocking: possible header attack with a header of: -1493106688 bytes.

    Anyone know what's going on here?
     
  2. mischa2k

    mischa2k

    Joined:
    Sep 4, 2015
    Posts:
    4,347
    It could indicate that your server is receiving random internet noise (or intentionally malformed packets).
    Telepathy protects against those attacks.
    However, you should definitely use our default KCP transport. It's a lot better.
     
    ToastSub likes this.
  3. ToastSub

    ToastSub

    Joined:
    Apr 8, 2023
    Posts:
    2
    Alright, switched to KCP and everything seems to be good. Thank you.
     
    mischa2k likes this.