DNS Exploit Attempts??
Sten Carlsen
ccc2716 at vip.cybercity.dk
Thu Jul 31 01:07:41 UTC 2008
BTW: if you suspect your cache has been poisoned, would more than just
flushing the cache be needed to remove the badness? Other than the
obvious: upgrade to a safe version and disable recursing for that audience.
Jeff Lightner wrote:
> Yep.
>
>
> Recursion and cache query are both prohibited from outside - that was
> actually done before the exploit patch because they'd been flagged in a
> PCI compliance scan.
>
>
>
> ________________________________
>
> From: Dawn Connelly [mailto:dawn.connelly at gmail.com]
> Sent: Wednesday, July 30, 2008 4:59 PM
> To: Jeff Lightner
> Cc: Graeme Fowler; bind-users at isc.org
> Subject: Re: DNS Exploit Attempts??
>
>
>
> No worries. This particular "attack" isn't new...it's probably just
> being used a lot more. It's testing for low hanging fruit to target. If
> your recursion is open to the world, it will be wicked easy to poison
> your cache... moral of the story- patching is great, but make sure your
> recursion ACLs are in place too.
>
> On Wed, Jul 30, 2008 at 1:16 PM, Jeff Lightner <jlightner at water.com>
> wrote:
>
> The point in my post was asking if there was a known thing that occurred
> that would have suddenly have spawned more of these kinds of queries
> than in the past given that various people are seeing them.
>
> Obviously I could research individual addresses - but my question wasn't
> how to research them but rather if there was a known badness that had
> suddenly started spawning more of them given that I was seeing them as
> others also apparently were.
>
> To that end Dawn's post more closely attempted to answer that than
> Graeme's.
>
> I have by the way already created a blacklist. Again I was just
> wondering if there was something new and exciting happening.
>
>
> -----Original Message-----
> From: bind-users-bounce at isc.org [mailto:bind-users-bounce at isc.org] On
>
> Behalf Of Dawn Connelly
> Sent: Wednesday, July 30, 2008 4:01 PM
> To: Graeme Fowler
> Cc: bind-users at isc.org
> Subject: Re: DNS Exploit Attempts??
>
> True that...but this is most likely the script that was causing the
> badness
> he was seeing:
> http://www.opennet.ru/dev/fsbackup/src/1.2pl1_to_1.2pl2.diff
> It was written by the same guy that owns the IP address space that he
> was
> seeing the . requests coming from. It should still be blacklisted.
>
> On Wed, Jul 30, 2008 at 12:46 PM, Graeme Fowler <graeme at graemef.net>
> wrote:
>
>
>> On Wed, 2008-07-30 at 13:08 -0400, Jeff Lightner wrote:
>>
>>> Someone had apparently posted on a Fedora forum that seeing the high
>>> level of query cache denied was a sign of people trying the exploit
>>>
> but
>
>>> someone else here said it wasn't a symptom of the exploit.
>>>
>> That's not *quite* correct (well, not even correct actually, but that
>> sounds churlish).
>>
>> I said that the addresses listed in the post on the fedora-users list
>> were actually directly related to research work being done by Dan
>> Kaminsky and/or some people at a .edu connected to him.
>>
>> The OP of the message fired off in a panic, IMO, without doing any
>> homework whatsoever.
>>
>>
>>> However, on returning to my office I too saw a dramatic increase in
>>>
> the
>
>>> number of these. If they aren't for the exploit does someone know
>>>
> why
>
>>> they increased?
>>>
>> If you've seen a dramatic increase in log entries, have you done any
>> work at all to see where they're coming from? Pound to a penny, if you
>> find they're from an educational institution you'll be able to fire
>>
> off
>
>> an email to someone there (look in WHOIS for the contact details for
>> starters) and they'll tell you. If they're from Nigeria, Chinese ISPs,
>> Russia, or a bunch of colo/hosting places in the US or Europe (or
>>
> other
>
>> common malware sources, yours will differ from mine) then they're
>> probably scans from less friendly types.
>>
>> There's an interesting message on the OARCI dnsops list here:
>>
>> http://lists.oarci.net/pipermail/dns-operations/2008-July/003110.html
>>
>> [note: the sender of that message is the originator of query-cache
>>
> scans
>
>> from Georgia Tech IP IPv4 space]
>>
>> I guess the important message here is: do some homework first. They
>>
> may
>
>> or may not be malicious, but having an indication either way is good
>> before you run into the woods with your shotgun.
>>
>> Graeme
>>
>>
>>
>>
>
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--
Best regards
Sten Carlsen
No improvements come from shouting:
"MALE BOVINE MANURE!!!"
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