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Re: SANS: DNS Bug Now Public?


From: "Darren Bolding" <darren () bolding org>
Date: Wed, 23 Jul 2008 12:16:41 -0700

After a bit of looking around, I have not been able to find a list of
firewalls/versions which are known to provide appropriate randomness in
their PAT algorithms (or more importantly, those that do not).

I would be very interested in such a list if anyone knows of one.

As a side note, most people here realize this but, while people mention
firewalls, keep in mind that if a load-balancer or other device is your
egress PAT device, you might be interested in checking those systems
port-translation randomness as well.

--D

On Wed, Jul 23, 2008 at 10:11 AM, Joe Abley <jabley () ca afilias info> wrote:


On 23 Jul 2008, at 12:16, Jorge Amodio wrote:

Let me add that folks need to understand that the "patch" is not a fix to a
problem that has been there for long time and
it is just a workaround to reduce the chances for a potential
attack, and it must be combined with best practices and
recommendations to implent a more robust DNS setup.


Having just seen some enterprise types spend time patching their
nameservers, it's also perhaps worth spelling out that "patch" in this case
might require more than upgrading resolver code -- it could also involve
reconfigurations, upgrades or replacements of NAT boxes too. If your NAT
reassigns source ports in a predictable fashion, then no amount of BIND9
patching is going to help.

(Reconfiguring your internal resolvers to forward queries to an external,
patched resolver which can see the world other than through NAT-coloured
glasses may also be a way out.)


Joe





-- 
-- Darren Bolding --
-- darren () bolding org --


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