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Re: [Acme] ACME vulnerabilities in SimpleHTTP due to common webservers' default virtual host semantics

Niklas Keller <me@kelunik.com> Thu, 19 November 2015 08:41 UTC

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Date: Thu, 19 Nov 2015 09:41:50 +0100
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From: Niklas Keller <me@kelunik.com>
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Subject: Re: [Acme] ACME vulnerabilities in SimpleHTTP due to common webservers' default virtual host semantics
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*push*

2015-11-13 16:35 GMT+01:00 Niklas Keller <me@kelunik.com>:

> This is a followup on "ACME vulnerabilities in SimpleHTTP and DVSNI due to
> common webservers' default virtual host semantics", since I don't have that
> mail in my archive (was not subscribed to the list back then), I can't
> respond directly to that thread. (Stupid mailing lists.)
>
> Could someone explain the exact vulnerability? Since those challenge
> payloads are bound to a specific domain, I don't see the problem.
> Additionally, I don't see why it's a problem with HTTPS, why is it
> mitigated by switching to HTTP? HTTP via port 80 has just the same
> semantics for default hosts as HTTPS via 443 has.
>
> Regards, Niklas
>

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