[dns-operations] Stunning security discovery: AXFR may leak information

wbrown at e1b.org wbrown at e1b.org
Tue Apr 14 19:49:33 UTC 2015

From: Paul Vixie <paul at redbarn.org>

> to me this harkens back to one of my earliest hacks to BIND4, which was
> to add an access list for TCP. of course in 1988 or whenever this was, i
> didn't realize that AXFR wasn't the only use of TCP, so i quickly had to
> patch BIND4 differently (ACL on zone transfers). fun times.
> the other thing i didn't realize at that time was the obvious need for
> an IETF BCP or FYI document saying that name servers should restrict
> zone transfers to "nobody" by default, and to provide an ACL to allow
> known good secondary servers to access them. had i written that RFC in
> 1988-ish, it might be common practice by now. (and that would have been
> a good time to say what RFC 5358 later said, too.)
> when i say that the internet is, and has always been, too open for the
> good of its users, i don't mean i want censorship. rather, i want
> admission control and access control to be the default -- all
> communities gated.

Perhpas if BIND came with a very minimal named.conf that included basic 
but typical configurations like not allowing zone transfers, a zone for, etc., new admins could be guided into making some good initial 

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