This is the mail archive of the
cygwin
mailing list for the Cygwin project.
RE: Possible Security Hole in SSHD w/ CYGWIN?
- From: "David Willis" <david_willis at comcast dot net>
- To: <cygwin at cygwin dot com>
- Date: Tue, 9 Feb 2016 07:56:15 -0800
- Subject: RE: Possible Security Hole in SSHD w/ CYGWIN?
- Authentication-results: sourceware.org; auth=none
- References:
- Reply-to: <cygwin at cygwin dot com>
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.
--
Problem reports: http://cygwin.com/problems.html
FAQ: http://cygwin.com/faq/
Documentation: http://cygwin.com/docs.html
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple