John Biederstedt
24/04/06, 00:00
This is a multi-part message in MIME format.
--_----------=_11454902188250
Content-Disposition: inline
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="ISO-8859-1"
MIME-Version: 1.0
X-Mailer: MIME::Lite 5022 (F2.72; T1.15; A1.62; B3.04; Q3.03)
Date: Wed, 19 Apr 2006 23:43:38 UT
Actually, according to microsoft, the dns client in XP was *intended* to
check to see if a dns lookup had failed earlier before going to the
hosts file.
We did ping the internal domain controller, added the bogus FQDN, and
tried again. None of that worked, because prior to the VPN working, and
lookup of the domain controller had failed, and been cached. So,
because the failiure was checked before the hosts file, once the VPN was
up, the dns lookups didn't work.
Oh yes, the XP install was factory Dell.
--_----------=_11454902188250
Content-Disposition: attachment; filename="ReFull-disclosureMicrosoftDNSresolverdeliberatelysabotage dhosts-filelookup.eml"
Content-Transfer-Encoding: 8bit
Content-Type: message/rfc822; name="ReFull-disclosureMicrosoftDNSresolverdeliberatelysabotage dhosts-filelookup.eml"
MIME-Version: 1.0
X-Mailer: MIME::Lite 5022 (F2.72; T1.15; A1.62; B3.04; Q3.03)
Date: Wed, 19 Apr 2006 23:43:38 UT
Received: from mx2.internal (mx2.internal [10.202.2.201])
by server4.messagingengine.com (Cyrus v2.3-alpha) with LMTPA;
Wed, 19 Apr 2006 18:22:39 -0400
X-Sieve: CMU Sieve 2.3
X-Spam-score: 0.0
X-Delivered-to: johnbiederstedt@imapmail.org
Received: from redir-mail-telehouse1.gandi.net (redir-mail-telehouse1.gandi.net [217.70.180.1])
by mx2.messagingengine.com (Postfix) with ESMTP id 58DC4B1AE
for <johnbiederstedt@imapmail.org>; Wed, 19 Apr 2006 18:22:47 -0400 (EDT)
Received: from eq1.spamarrest.com (eq2.spamarrest.com [66.150.163.135])
by glenlivet.gandi.net (Postfix) with ESMTP id 9D2C2445C70
for <john@johnsdomain.org>; Thu, 20 Apr 2006 00:22:37 +0200 (CEST)
Received: from [192.168.1.19] (c-67-169-126-55.hsd1.ca.comcast.net [67.169.126.55])
(using TLSv1 with cipher DES-CBC3-SHA (168/168 bits))
(No client certificate requested)
by eq1.spamarrest.com (Postfix) with ESMTP id 37DA060C1B9;
Wed, 19 Apr 2006 15:21:00 -0700 (PDT)
User-Agent: Microsoft-Entourage/11.2.3.060209
Date: Wed, 19 Apr 2006 15:22:32 -0700
Subject: Re: [Full-disclosure] Microsoft DNS resolver: deliberately
sabotagedhosts-file lookup
From: "Thor (Hammer of God)" <thor@hammerofgod.com>
To: <john@johnsdomain.org>, Bugtraq <bugtraq@securityfocus.com>
Message-ID: <C06C0638.3015%thor@hammerofgod.com>
Thread-Topic: [Full-disclosure] Microsoft DNS resolver: deliberately
sabotagedhosts-file lookup
Thread-Index: AcZj/8BC/w4Jj8/yEdqmjgAWy6MfyA==
In-Reply-To: <20060417123318.20887.qmail@securityfocus.com>
Mime-version: 1.0
Content-type: text/plain;
charset="US-ASCII"
Content-transfer-encoding: 7bit
Then you've hosed your XP install. XP does not resolve cached addresses
before the hosts file.
Ping your 1918 domain controller. Add a bogus entry for the FQDN of the
same machine. Ping it again. Hosts file overrides. I'm not sure what you
mean by "DNS failiures" though. Please post something we can all use to
test your rotten but unsurprising behavior.
Oh, and before getting very frustrated, even in your hosed install, just try
a "IPCONFIG /flushdns" next time.
t
On 4/17/06 5:33 AM, "john@johnsdomain.org" <john@johnsdomain.org> spoketh to
all:
> The XP DNS client has other problems as well. It caches DNS failiures
> (arguably out of spec with the RFC, BTW), screwing up VPNs if you're VPNed
> into an internet network that has local domains which need to resolve to
> RFC1918 addresses. The cached failed lookups get prefered to forced entries
> in the hosts file, if that is tried as a way of forcing the dns lookups to
> work. Very frustrating. So, this isn't much of a surprise. Rotten, yes,
> surprising, no.
>
>
--_----------=_11454902188250--
--_----------=_11454902188250
Content-Disposition: inline
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="ISO-8859-1"
MIME-Version: 1.0
X-Mailer: MIME::Lite 5022 (F2.72; T1.15; A1.62; B3.04; Q3.03)
Date: Wed, 19 Apr 2006 23:43:38 UT
Actually, according to microsoft, the dns client in XP was *intended* to
check to see if a dns lookup had failed earlier before going to the
hosts file.
We did ping the internal domain controller, added the bogus FQDN, and
tried again. None of that worked, because prior to the VPN working, and
lookup of the domain controller had failed, and been cached. So,
because the failiure was checked before the hosts file, once the VPN was
up, the dns lookups didn't work.
Oh yes, the XP install was factory Dell.
--_----------=_11454902188250
Content-Disposition: attachment; filename="ReFull-disclosureMicrosoftDNSresolverdeliberatelysabotage dhosts-filelookup.eml"
Content-Transfer-Encoding: 8bit
Content-Type: message/rfc822; name="ReFull-disclosureMicrosoftDNSresolverdeliberatelysabotage dhosts-filelookup.eml"
MIME-Version: 1.0
X-Mailer: MIME::Lite 5022 (F2.72; T1.15; A1.62; B3.04; Q3.03)
Date: Wed, 19 Apr 2006 23:43:38 UT
Received: from mx2.internal (mx2.internal [10.202.2.201])
by server4.messagingengine.com (Cyrus v2.3-alpha) with LMTPA;
Wed, 19 Apr 2006 18:22:39 -0400
X-Sieve: CMU Sieve 2.3
X-Spam-score: 0.0
X-Delivered-to: johnbiederstedt@imapmail.org
Received: from redir-mail-telehouse1.gandi.net (redir-mail-telehouse1.gandi.net [217.70.180.1])
by mx2.messagingengine.com (Postfix) with ESMTP id 58DC4B1AE
for <johnbiederstedt@imapmail.org>; Wed, 19 Apr 2006 18:22:47 -0400 (EDT)
Received: from eq1.spamarrest.com (eq2.spamarrest.com [66.150.163.135])
by glenlivet.gandi.net (Postfix) with ESMTP id 9D2C2445C70
for <john@johnsdomain.org>; Thu, 20 Apr 2006 00:22:37 +0200 (CEST)
Received: from [192.168.1.19] (c-67-169-126-55.hsd1.ca.comcast.net [67.169.126.55])
(using TLSv1 with cipher DES-CBC3-SHA (168/168 bits))
(No client certificate requested)
by eq1.spamarrest.com (Postfix) with ESMTP id 37DA060C1B9;
Wed, 19 Apr 2006 15:21:00 -0700 (PDT)
User-Agent: Microsoft-Entourage/11.2.3.060209
Date: Wed, 19 Apr 2006 15:22:32 -0700
Subject: Re: [Full-disclosure] Microsoft DNS resolver: deliberately
sabotagedhosts-file lookup
From: "Thor (Hammer of God)" <thor@hammerofgod.com>
To: <john@johnsdomain.org>, Bugtraq <bugtraq@securityfocus.com>
Message-ID: <C06C0638.3015%thor@hammerofgod.com>
Thread-Topic: [Full-disclosure] Microsoft DNS resolver: deliberately
sabotagedhosts-file lookup
Thread-Index: AcZj/8BC/w4Jj8/yEdqmjgAWy6MfyA==
In-Reply-To: <20060417123318.20887.qmail@securityfocus.com>
Mime-version: 1.0
Content-type: text/plain;
charset="US-ASCII"
Content-transfer-encoding: 7bit
Then you've hosed your XP install. XP does not resolve cached addresses
before the hosts file.
Ping your 1918 domain controller. Add a bogus entry for the FQDN of the
same machine. Ping it again. Hosts file overrides. I'm not sure what you
mean by "DNS failiures" though. Please post something we can all use to
test your rotten but unsurprising behavior.
Oh, and before getting very frustrated, even in your hosed install, just try
a "IPCONFIG /flushdns" next time.
t
On 4/17/06 5:33 AM, "john@johnsdomain.org" <john@johnsdomain.org> spoketh to
all:
> The XP DNS client has other problems as well. It caches DNS failiures
> (arguably out of spec with the RFC, BTW), screwing up VPNs if you're VPNed
> into an internet network that has local domains which need to resolve to
> RFC1918 addresses. The cached failed lookups get prefered to forced entries
> in the hosts file, if that is tried as a way of forcing the dns lookups to
> work. Very frustrating. So, this isn't much of a surprise. Rotten, yes,
> surprising, no.
>
>
--_----------=_11454902188250--