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Date: Tue, 11 Dec 2012 10:22:46 -0200
From: Ulisses Montenegro <>
To: Scott Ferguson <>
Subject: Re: Google's robots.txt handling

If I understand the OP correctly, he is not stating that listing something
in robots.txt would make it inaccessible, but rather that Google indexes
the robots.txt files themselves, and makes the contexts of those available
for query. So, in a way, they make it easier for Google search results
harvesters to find sites which host files/directories of known
applications, while Google does not index those directories/files
themselves because it follows the robots.txt restrictions. In a nutshell:

[Attacker] Google, show me sites that have public /wp-admin/ directories.
[Google] I don't know about that, I was not allowed to index those.
[Attacker] Ok, so show me the hosts that have robots.txt files which
disallow indexing /wp-admin/ directories, then...
[Google] Sure thing, here you go!

Yes, the fact that those resources are out there in the open makes the
effort of hiding them from Google crawlers rather useless, but still Google
should not allow queries on the contents of robots.txt files, as it sort of
beats the purpose of disallowing stuff from being indexed...

On Mon, Dec 10, 2012 at 8:19 PM, Scott Ferguson <> wrote:

> > /From/: Hurgel Bumpf <l0rd_lunatic () yahoo com>
> > /Date/: Mon, 10 Dec 2012 19:25:39 +0000 (GMT)
> > ------------------------------------------------------------------------
> > Hi list,
> >
> >
> > i tried to contact google, but as they didn't answer my email,  i do
> forward this to FD.
> > This "security" feature is not cleary a google vulnerability, but
> exposes websites informations that are not really
> > intended to be public.
> >
> > (Additionally i have to say that i advocate robots.txt files without
> sensitive content and working security mechanisms.)
> >
> > Here is an example:
> >
> > An admin has a public webservice running with folders containing
> sensitive informations. Enter these folders in his
> > robots.txt and "protect" them from the indexing process of spiders. As
> he doesn't want the /admin/ gui to appear in the
> > search results he also puts his /admin in the robots text and finaly
> makes a backup to the folder /backup.
> >
> > <snipped>
> >
> > This shouldn't be a discussion about bad practice but the google feature
> itself.
> >
> > Indexing a file which is used to prevent indexing.. isn't that just
> paradox and hypocrite?
> >
> > Thanks,
> >
> >
> > Conan the bavarian
> Your point eludes me - Google is indexing something which is publicly
> available. eg.:- curl http://somesite.tld/robots.txt
> So it seems the solution to the "question" your raise is, um, nonsensical.
> If you don't want something exposed on your web server *don't publish
> references to it*.
> The solution, which should be blindingly obvious,  is don't create the
> problem in the first place. Password sensitive directories (htpasswd) -
> then they don't have to be excluded from search engines (because listing
> the inaccessible in robots.txt is redundant).  You must of missed the
> first day of web school.
> Kind regards.
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