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Re: DNS resolver library exploit.
- To: misc@openbsd.org
- Subject: Re: DNS resolver library exploit.
- From: Nick Nauwelaerts <nick@wanadoo.be>
- Date: Mon, 1 Jul 2002 12:44:20 +0200
- References: <20020630195131.64509.qmail@web14107.mail.yahoo.com> <20020630142608.7f53a25a.grendel@zeitbombe.org>
On Sun, 30 Jun 2002 14:26:08 +0000
tedu <grendel@zeitbombe.org> wrote:
> If the resolver gets a bad reply, it can crash/be exploited.
> Typically, you trust your DNS servers to some extent. My
> understanding is that you can only be attacked by the people owning
> the DNS servers you use.
Most client-side programs lack the logic to do full recursive DNS
look-ups, and so forward that request to their (ISP's or local)
nameserver. That nameserver does the searching for the client and
returns the answer. Now, some DNS servers re-write the information they
receive from upstream servers, and some just pass it on without the
rewrite. So yes, I think you might be vulnerable to this even when using
trusted DNS servers.
There was a tread on bugtraq or vuln-dev about this, you might want to
have a look at that:
http://online.securityfocus.com/archive/82/279431
// nick