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

From: Gadi Evron <ge(at)linuxbox.org>
Date: Fri Jul 27 2007 - 00:40:55 EDT

This is Paul Vixie's response on this, when I asked him for verification:

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this bug has been reported over and over again for a dozen years. it's odd to have to keep fixing it-- i fixed it in bind4 and bind8 when theo de raadt offered me his random number generator to use. bind9 should've used that same one but apparently didn't. note that with this fix, the difficulty in poisoning someone's cache rises from "a few tens of seconds" to "a few minutes". it's a 16-bit field. not a lot of room for randomness or unpredictability. only DNSSEC, a protocol change, fixes this problem, which is fundamentally a protocol problem. but since folks just won't leave it alone and keep on reporting it year after decade, we will keep on improving our random number generator for this dinky little 16-bit field. i just wish the reporters wouldn't be so smarmy and self congradulatory about it. it's not like this hasn't been reported, and fixed, many times by many others.

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         Gadi. Received on Fri Jul 27 12:53:55 2007