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Re: [Full-disclosure] DNS bind attacks



Other than the fact they may somehow notice this and start trying to
autoban sites you should be fine. Since he is spoofing it would be hard for
him to tell without trying it out on a box he controls. If anything gets
autobanned you really need then just whitelist it, if you can think of such
places before hand then go ahead and whitelist them now.

Just be aware in case its not a ddos but really part of some exploit of
sorts, as owning a bind server is obviously very appealing. Now if any
would be a good time to do a double check on your security measures but in
all likelihood it seems like a fairly weak attack and your measures should
be fine.

That or we are both missing some glaring piece of information.
On Jan 26, 2012 3:36 AM, "J. von Balzac" <jhm.balzac@xxxxxxxxx> wrote:

> I'm seeing a lot of hosts in my named logs (I mean log files, it's not
> like I am naming my poop)
>
> ...ok... silly joke hehe
>
> So anyway, named bind is reporting a lot of denied queries of type
> 'isc.org/ANY/IN'. I'm not looking for a solution - I have one (which
> is to immediately block the IPs for port 53 after as few as one denied
> query) - but I want to warn server admins who haven't spotted both
> these queries and other denied queries.
>
> Common sense suggests that these hosts are probably spoofed IPs. Looks
> like an effective way to ddos a host: request an arbitrary DNS record
> with a spoofed IP and let the server reply to the spoofed IP in
> whatever way. Do that with many hosts and there is your denial of
> service.
>
> A side effect is that when you block the IP, you're blocking something
> that isn't really doing anything wrong as it's a spoofed IP
>
> But ok, I'm not too sure of this so please shoot holes in my theory or
> suggest better fixes/workarounds/...
>
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_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/