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From: "David Willis" <david_willis@comcast.net>
To: <cygwin@cygwin.com>
Subject: RE: Possible Security Hole in SSHD w/ CYGWIN?
Date: Tue, 09 Feb 2016 15:56:00 -0000	[thread overview]
Message-ID: <018801d16352$68a6b940$39f42bc0$@comcast.net> (raw)
In-Reply-To: 

Sorry for starting a new thread w/ the reply, forgot to subscribe before
posting my question yesterday...

Thanks for getting back so quickly

Yes, I have read that page pretty much from top to bottom, and as far as I
know I have configured sshd and the user accounts correctly. I have a
non-privileged, disabled account named "sshd", as well as a privileged
account called "cyg_server". Privilege separation seems to be working fine -
i.e. when the request for a connection comes in the process is running as
"sshd", then it spawns a privileged process running as "cyg_server" once the
user is authenticated.

However no I am not logging in with a password; I have setup public key
authentication.

And the user I'm being connected as (as seen from the file share server) is
not the "sshd" user account, it is the privileged "cyg_server" user account.
Although that account has no rights to logon interactively or thru Terminal
Services, it is a privileged account on the file server (because the file
server is also running CYGWIN and thus must allow privileged rights to that
account as well). I should clarify that in my case, cyg_server is a domain
account (not a local account).

And the way I can verify, is that I have a folder on that share that the
user I am authenicating as does not have rights do view, but cyg_server does
(because Administrators on that server do), and when I connect as my user
via SSHD to any one of my other machines on the domain running CYGWIN, I can
then navigate to and read the contents of that file share when I shouldn't
be able to. If I try to do the same thing, from the same account, but on my
machine locally without connecting to any other CYGWIN SSH server, I get a
"Permission denied", which is what I would expect.

Thank you for your help on this.

David

----------------------------------------------------------------------------
--------------------------

Did you read https://cygwin.com/cygwin-ug-net/ntsec.html, configured sshd
and the user accounts correctly and are logging in with a password using
either of the methods described?

FWIW, I'm seeing the connected user as the one that I logged into via ssh. 
In fact the sshd user account doesn't have any network access rights anyway,
so I couldn't connect to any network share if that acount would be used.


Regards,
Achim.



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             reply	other threads:[~2016-02-09 15:56 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-09 15:56 David Willis [this message]
  -- strict thread matches above, loose matches on Subject: below --
2016-02-10  4:39 David Willis
2016-02-10  4:57 ` Stephen John Smoogen
2016-02-10  5:21   ` David Willis
2016-02-12 22:27     ` David Willis
2016-02-13  8:34       ` Achim Gratz
2016-02-13 21:15         ` David Willis
2016-02-14  0:34           ` Erik Soderquist
2016-02-14  1:29             ` David Willis
2016-02-14  1:48               ` Erik Soderquist
2016-02-14 10:49           ` Achim Gratz
2016-02-14  0:14         ` Erik Soderquist
2016-02-14  1:37           ` David Willis
2016-02-14 10:49           ` Achim Gratz
2016-02-14 18:36             ` Erik Soderquist
2016-02-15 12:11               ` Corinna Vinschen
2016-02-17  4:55                 ` David Willis
2016-02-17  9:43                   ` Corinna Vinschen
2016-02-18 15:13                     ` Corinna Vinschen
2016-02-18 17:10                       ` Erik Soderquist
2016-02-19 11:10                         ` Corinna Vinschen
2016-02-19 16:38                           ` Erik Soderquist
2016-02-20 19:53                       ` David Willis
2016-02-13  1:04     ` Erik Soderquist
2016-02-13 20:04       ` David Willis
2016-02-09  6:43 David Willis
2016-02-09  7:53 ` Achim Gratz

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