[zeromq-dev] zmq_server can be remotely crashed with telnet

Pieter Hintjens ph at imatix.com
Mon Mar 30 19:04:02 CEST 2009


On Mon, Mar 30, 2009 at 2:16 PM, Martin Sustrik <sustrik at fastmq.com> wrote:

> I've checked this. It seems that when you press Ctrl+C in telnet, it
> sends following 5 bytes to 0MQ: ff f4 ff fd 06 (wireshark interprets the
> sequence as SIGCOMP, see RFC3321). I have no idea what is it supposed to
> mean.

It's a TELNET escape sequence...

> There's no clean way to deal with the problem. The only possibility is
> to allow user to specify maximal acceptable size of the message - if the
> size of incoming message is larger than the threshold, the connection
> would be killed.

That is the clean way to deal with the problem - AMQP does this by
defining a negotiable maximum frame size.

-Pieter



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