Re: Terminal Services Security Issue with Cached Credentials

OK I did some testing on my end. I found on my test domain that even if I
have saved credentials, that I could not use them to logon to the TS if it
is configured to always prompt for password as I was prompted for a
password. So you may want to try that out on your end and at least that
should prevent users from logging onto the TS with cached credentials .

Steve


"Steven L Umbach" <n9rou@xxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:%23nTvWNBHIHA.280@xxxxxxxxxxxxxxxxxxxxxxx
Thanks for the update. When I get some time I will look into it further
and see if I can come up with anything else.As far as admin workstations,
there should not be that many of them and they need to be secured from the
general populace, and those that logon to them should know better in my
opinion. But still I understand your want for policy to work as stated.
You may also want to post in one of the Terminal Services newsgroups to
see if anyone there has any ideas.

Steve


<bryan.rutkowski@xxxxxxxxx> wrote in message
news:1193850026.851697.222080@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I thought the same thing, only problem is I went to test that and you
can still edit your password in MSTSC. If you entered the credentials
before the new GPO setting was applied to disable saving passwords you
have that option forever or until you manually delete it within MSTSC
(Hence my problem). So they could just click the edit button and
enter their new password and it saves it... So no luck there. We
have a MS guy here this week and I asked him about this, hopefully he
is able to find an answer. I'll let you know what I hear. I am
surprised this isn't a well known bug/issue, you would think this
would be a pretty big security risk as a hacker could maybe get access
to an admins workstation then get direct access to a DC or other
server.

On Oct 30, 10:09 pm, "Steven L Umbach" <n9...@n0-spam-for-me-
comcast.net> wrote:
Maybe it is a good time to force everyone to change their passwords. You
could try starting with a few domain users to see if that solves your
issue.

Steve

<bryan.rutkow...@xxxxxxxxx> wrote in message

news:1193770757.630027.69130@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

I tried the User Configuration setting as well, no luck, previously
entered credentials could still be used. Also setting the requirement
on the server doesn't help much as the password is still stored on the
workstation. I really need to make sure those passwords are removed
from the workstations. I know the policies are working as any new
connection settings do not allow me to save credentials, it forces me
to enter them each time.

Bryan

On Oct 29, 9:28 pm, "Steven L Umbach" <n9...@n0-spam-for-me-
comcast.net> wrote:
I noticed that the do not allow passwords to be saved is in computer
configuration and user configuration. You may want to try and enable
it
in
both places to see what happens and also run rsop.msc on a computer
where
it
does not seem to be working to make sure the user/computer is within
the
scope of management of the GPO that you configured. Also you can
configure
to always prompt for password on the TS itself in administrative
tools/TS
configuration - connections selecting Microsoft RDP in the right
window,
select properties/logon settings - always prompt for password.

Steve

<bryan.rutkow...@xxxxxxxxx> wrote in message

news:1193676782.720415.219620@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

I have noticed a security issue regarding the Cached Credentials
(Saved Username and Passwords) in Terminal Services. I had
previously
run Terminal Services and connected to multiple servers entering my
credentials and saving them so I wouldn't have to enter them again.
Recently though I have been asked to disable this feature for
everyone
in the company. So I have been testing a solution on my
workstation
to force users to enter their credentials and clear out their old
saved credentials so they can't use that function anymore.

I found the following GPO settings which are supposed to force
entering of credentials.

-----
"Always prompt client for password upon connection"

Specifies whether Terminal Services always prompts the client for a
password upon connection.

You can use this setting to enforce a password prompt for users
logging on to Terminal Services, even if they already provided the
password in the Remote Desktop Connection client.

If the status is set to Enabled, users cannot automatically log on
to
Terminal Services by supplying their passwords in the Remote
Desktop
Connection client. They are prompted for a password to log on.
-----

I also found this GPO

-----
"Do not allow passwords to be saved"

Controls whether passwords can be saved on this computer from
Terminal
Services clients.

If you enable this setting the password saving checkbox in Terminal
Services clients will be disabled and users will no longer be able
to
save passwords. When a user opens an RDP file using the Terminal
Services client and saves his settings, any password that
previously
existed in the RDP file will be deleted.

If you disable this setting or leave it not configured, the user
will
be able to save passwords using the Terminal Services client.
-----

Now one would think when I enable both of these GPO's I would no
longer be able to login with saved usernames and passwords in
Terminal
Services.

The problem is when I open my Terminal Services client (MSTSC) I am
still able to used cached credentials. I would have to click the
link
to manually delete my saved credentials, otherwise it will keep
them,
even though the GPO says I can't use them. Essentially making the
GPO
settings worthless.

Does anyone know how to make it so it FORCES users to enter their
credentials every time, even if they saved them before the GPO was
set. Or is their a way to delete them remotely?






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