bugtraq - Re: Privacy leak in VeriSign's SiteFinder service #2

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Date: Thu, 25 Sep 2003 13:58:12 +0200 (CEST)
From: Marco Ivaldi <raptor@...eadbeef.info>
To: Henning Rust <Henning.Rust@...d.uni-hannover.de>
Cc: "BUGTRAQ@...URITYFOCUS. COM" <BUGTRAQ@...urityfocus.com>
Subject: Re: Privacy leak in VeriSign's SiteFinder service #2

> Up to now, e-mails addressed to misspelled mail domains will not be sent
> to Verisign's Fake-SMTP-service as MX records are used for mail-domain
> resolving. Verisign did not set up wildcard MX records.

That's not entirely correct. Since every host in non-existant domain now
resolves to 64.94.110.11 (DNS record type A), all email traffic with
misspelled recipient domain is actually forwarded to Verisign's
sitefinder, without the need for a specific MX record:

root@...doo:~# host jasfkjhaf.com
jasfkjhaf.com           A       64.94.110.11

E.g., try sending a test email to whatever@...-existant, you'll get
something like that:

<test@...fkjhaf.com>:
64.94.110.11 does not like recipient.
Remote host said: 550 <unknown[X.X.X.X]>: Client host rejected: The
domain you are trying to send mail to does not exist.
Giving up on 64.94.110.11.

:raptor
-- 
Marco Ivaldi
Antifork Research, Inc.   http://0xdeadbeef.info/
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