Re: Windows DNS Cache Poisoning by Forwarder DNS Spoofing

Hello Makoto,

Thank you for the clarification, Tim.
That is exactly what I wanted to say. :)

By the way, as regards recent Bind 9, birthday attack is much more
difficult to conduct because even if the attacker sends multiple
simultaneous recursive queries, Bind 9 aggregates these queries.

Aggregating queries would definitely help if you assume the attacker can
make recursive queries.

However, it was my understanding (which could be completely wrong) that
BIND 9 reuses sockets for multiple queries, unlike previous versions,
and this makes spoofed attacks easier in another respect. (Of course
this all has nothing to do with the Windows-specific flaw.)


In addition, there is a patch written by Jinmei-san for Bind 9.4.0
(current release) to randomize source ports.

http://www.jinmei.org/bind-9.4.0-portpool.patch
http://member.wide.ad.jp/tr/wide-tr-dns-bind9-portpool-01.txt
(technical report from WIDE project in Japanese)

That's good, that at least someone is trying to do this in BIND.

thanks for the info,
tim

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