Re: "BIND 9 DNS Cache Poisoning" by Amit Klein (Trusteer)

On 24 Jul 2007 17:40:35 -0000, securityfocus@networkontap.com
<securityfocus@networkontap.com> wrote:
> I don't exactly see how this is new "News" since Zalewski's paper on TCP 
> sequence number analysis (which included analysis of versions of BIND):
>
> http://lcamtuf.coredump.cx/newtcp/

That article does not deal with attacks on BIND's PRNG.

As far as I can tell, Joe Stewart extended Zalewski's TCP sequence
number analysis to BIND's transaction IDs - however I don't think
Stewart's paper "DNS Cache Poisoning – The Next Generation" (
www.lurhq.com/dnscache.pdf ) goes as far as the recent BIND advisory
here - http://www.isc.org/sw/bind/bind-security.php:

"The DNS query id generation is vulnerable to cryptographic analysis
which provides a 1 in 8 chance of guessing the next query id for 50%
of the query ids. This can be used to perform cache poisoning by an
attacker."

I don't think that Amit's attack has been described before.

cheers,
Jamie
--
Jamie Riden / jamesr@europe.com / jamie@honeynet.org.uk
UK Honeynet Project: http://www.ukhoneynet.org/