[Lukasa]

> It's the same as if you blamed the TLS/SSL RFC for being responsible for the heartbleed bug in OpenSSL - It makes no sense.

It makes some sense.

Features are attack surface. Each extra feature or option your protocol enables is more code you need to manage. So careful decisions need to be made: just because you can easily specify a feature for many use-cases in your protocol doesn't mean you should, because once you spec it people might just use it.

For heartbleed, for example, why was the TLS Heartbeat extension ever specified for TLS over reliable protocols? It serves no purpose: TCP has TCP_KEEPALIVE if that's a thing you need. But it was specified, and because it was specified it was implemented, and then it became attack surface that needed to be protected. It wasn't. So I guarantee to you that if RFC 6520 had been more restricted in scope, the Heartbleed attack would not have happened (or would have been a much more minor story, I can't remember if Heartbleed affected only the TLS and not the DTLS implementation).