[secdir] secdir review of draft-ietf-httpauth-basicauth-update-06 - security considerations on counterfeiting attacks
Julian Reschke <julian.reschke@gmx.de> Fri, 20 February 2015 13:53 UTC
Return-Path: <julian.reschke@gmx.de>
X-Original-To: secdir@ietfa.amsl.com
Delivered-To: secdir@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 8BFE31A7D81; Fri, 20 Feb 2015 05:53:23 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Level:
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=ham
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id dQEbTaRqC0T2; Fri, 20 Feb 2015 05:53:21 -0800 (PST)
Received: from mout.gmx.net (mout.gmx.net [212.227.17.21]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 104391A710C; Fri, 20 Feb 2015 05:53:21 -0800 (PST)
Received: from [192.168.1.26] ([217.91.35.233]) by mail.gmx.com (mrgmx102) with ESMTPSA (Nemesis) id 0Lv8hi-1XOpmz22SY-010OSP; Fri, 20 Feb 2015 14:53:00 +0100
Message-ID: <54E73C32.6070108@gmx.de>
Date: Fri, 20 Feb 2015 14:52:50 +0100
From: Julian Reschke <julian.reschke@gmx.de>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0
MIME-Version: 1.0
To: "http-auth@ietf.org" <http-auth@ietf.org>
References: <874mqjd49v.fsf@alice.fifthhorseman.net> <54E50FC3.9080708@gmx.de> <871tllbw2c.fsf@alice.fifthhorseman.net> <54E6348A.3080606@gmx.de> <87mw49ac9h.fsf@alice.fifthhorseman.net> <54E648B9.6030606@gmx.de> <9A93C4F9-C14E-410E-81B7-E36E05270FD2@gbiv.com>
In-Reply-To: <9A93C4F9-C14E-410E-81B7-E36E05270FD2@gbiv.com>
Content-Type: text/plain; charset="windows-1252"; format="flowed"
Content-Transfer-Encoding: 7bit
X-Provags-ID: V03:K0:moybVFRhPayWO/el3nE88vk+uXPw5ZD0U6//Ghp9yFtblo7CkF5 YoOKtUBgvuSfQj0mpwFyPZkZQiYJ246fD4KYvTuf1SMaWAG+ocEkYpeS2hk6wI28nn58n0j HOL8FI3MGy0XplzO9fVGG2nmdQju5JVP+FviwcJ46Y2x9D2CSHzjrqOqPhd7/1/820CzQWl tKo+AS1SwRnAofJz6m6Iw==
X-UI-Out-Filterresults: notjunk:1;
Archived-At: <http://mailarchive.ietf.org/arch/msg/secdir/If_fHxagz5QTrl3YZs8HRGZT2kc>
Cc: "secdir@ietf.org" <secdir@ietf.org>, "Roy T. Fielding" <fielding@gbiv.com>, "http-auth@ietf.org" <http-auth@ietf.org>, iesg@ietf.org, draft-ietf-httpauth-basicauth-update.all@tools.ietf.org
Subject: [secdir] secdir review of draft-ietf-httpauth-basicauth-update-06 - security considerations on counterfeiting attacks
X-BeenThere: secdir@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Security Area Directorate <secdir.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/secdir>, <mailto:secdir-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/secdir/>
List-Post: <mailto:secdir@ietf.org>
List-Help: <mailto:secdir-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/secdir>, <mailto:secdir-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 20 Feb 2015 13:53:23 -0000
On 2015-02-20 00:06, Roy T. Fielding wrote: > ... >>>>> And sorry, one more question arises for me on re-read. i'm not sure i >>>>> understand what this means: >>>>> >>>>> Server implementers SHOULD guard against the possibility of this sort >>>>> of counterfeiting by gateways or CGI scripts. In particular it is >>>>> very dangerous for a server to simply turn over a connection to a >>>>> gateway. That gateway can then use the persistent connection >>>>> mechanism to engage in multiple transactions with the client while >>>>> impersonating the original server in a way that is not detectable by >>>>> the client. >>>>> >>>>> How should the server guard against this attack? what sort does it mean >>>>> to "turn over a connection to a gateway"? does "gateway" mean >>>>> "transparent HTTP proxy" or does it refer to something else? Sorry if >>>>> this is elementary stuff, but the term "gateway" only appears in this >>>>> paragraph. >>>> >>>> That text is present in RFC 2617; I don't understand it completely either. > > This is about web server internals. Back in the early days, when HTTP was > limited to one request per connection, there was a thing called NPH scripts > that would allow a script to directly respond to the client instead of their > response being framed by the server; a trivial implementation could hand > off the file descriptor to the script and exit. However, that kind of > implementation became a potential security hole when persistent connections > were introduced, since the script could redirect the client to a > protected space within the same origin (controlled by someone else) > and receive the redirected request within the script input, bypassing the > web server's normal request-target hierarchy and collecting the credentials. > The solution is to never delegate message framing. > ... Thanks for the explanation, Roy. I have changed that paragraph to: > Basic authentication is also vulnerable to spoofing by counterfeit > servers. If a user can be led to believe that she is connecting to a > host containing information protected by Basic authentication when, > in fact, she is connecting to a hostile server or gateway, then the > attacker can request a password, store it for later use, and feign an > error. Server implementers ought to guard against this sort of > counterfeiting; in particular, software components which can take > over control over the message framing on an existing connection (for > instance, "NPH" ("non parsing of headers") scripts) need to be used > carefully or not at all. (<http://trac.tools.ietf.org/wg/httpauth/trac/changeset/126>) Best regards, Julian
- [secdir] secdir review of draft-ietf-httpauth-bas… Daniel Kahn Gillmor
- Re: [secdir] secdir review of draft-ietf-httpauth… Julian Reschke
- Re: [secdir] secdir review of draft-ietf-httpauth… Julian Reschke
- Re: [secdir] secdir review of draft-ietf-httpauth… Daniel Kahn Gillmor
- Re: [secdir] secdir review of draft-ietf-httpauth… Julian Reschke
- Re: [secdir] secdir review of draft-ietf-httpauth… Daniel Kahn Gillmor
- Re: [secdir] secdir review of draft-ietf-httpauth… Julian Reschke
- Re: [secdir] [http-auth] secdir review of draft-i… Bjoern Hoehrmann
- Re: [secdir] [http-auth] secdir review of draft-i… Kathleen Moriarty
- Re: [secdir] [http-auth] secdir review of draft-i… Kathleen Moriarty
- Re: [secdir] [http-auth] secdir review of draft-i… Roy T. Fielding
- Re: [secdir] [http-auth] secdir review of draft-i… Daniel Kahn Gillmor
- Re: [secdir] [http-auth] secdir review of draft-i… Roy T. Fielding
- Re: [secdir] secdir review of draft-ietf-httpauth… Julian Reschke
- [secdir] secdir review of draft-ietf-httpauth-bas… Julian Reschke
- [secdir] [http-auth] secdir review of draft-ietf-… Julian Reschke
- Re: [secdir] secdir review of draft-ietf-httpauth… Julian Reschke