Thanks Kirk
That was my worry here. Will have to rethink this.
As an answer to someone who asked about connecting directly over tcp/ip, the
printing functions are fine, it's the scanning side of things that can use
either SMB or ftp. We don't have capacity for ftp (yet!) but look to be
heading that way.
Thanks also to Bob for the excellent article.
As we grow, the potential for there being more savvy users who go unnoticed
is greater and therefore more worrisome when it comes to things like this.
Murad
-----Original Message-----
From: Soluk, Kirk [mailto:kmsoluk@umich.edu]
Sent: Friday, May 06, 2005 1:20 AM
To: Murad Talukdar; ?????? ??????
Cc: focus-ms@securityfocus.com
Subject: RE: To disable SMB packet and secure channel signing enforcement on
Windows Server 2003-based domain controllers
It's a negotiation. If the two ends (running NT4 SP3 or higher) have
signing "enabled", they'll negotiate it.
The problem is that any MITM can simply do a downgrade attack and say
"don't negotiate". So "enabling" signing (but not requiring it) doesn't
help you wrt a malicious MITM.
-----Original Message-----
From: Murad Talukdar [mailto:talukdar_m@subway.com]
Sent: Wednesday, May 04, 2005 11:26 PM
To: '?????? ??????'
Cc: focus-ms@securityfocus.com
Subject: RE: To disable SMB packet and secure channel signing
enforcement on Windows Server 2003-based domain controllers
Excellent. This is now working according to Laura's/????? ?????
settings.
Thanks to everyone. I've learnt a lot from this single issue.
One last question, with the whenever possible option. According to ?????
?????, the DCs will now communicate insecurely with my printer, but does
this mean it would communicate insecurely with some 'unknown' machine
too.
What I'm trying to work out, I guess, is how does it 'decide' when it
should communicate insecurely--what test does it carry out? Is it
treating the scanner as a member server or a client?
As the whole worry here is MITM's --are there ones which could be
utilized now that I have set the network server to digitally sign always
but the clients and the members to do it whenever possible?
I'm thinking the risk is greatly reduced but is it removed 'completely'?
Murad
-----Original Message-----
From: ?????? ?????? [mailto:morsin@eastbridge.tula.ru]
Sent: Wednesday, May 04, 2005 10:52 PM
To: Murad Talukdar
Subject: Re: To disable SMB packet and secure channel signing
enforcement on Windows Server 2003-based domain controllers
----- Original Message -----
1. From Administrative Tools open Domain Controller Security Policy 2.
Smile
3. Select \Security Settings\Local Policies\Security Options folder.
4. In
the details pane, double-click Microsoft network server: Digitally
sign
communications (always), and then click Disabled to prevent SMB packet
signing from being required. 5. Click OK. 6. In the details pane,
double-click Domain member: Digitally encrypt or sign secure channel
data
(always), and then click Disabled to prevent secure channel signing
from
being required. 7. Click OK.
1. Return back to "Enabled" secure channel ecnryption requirement. SMB
file
sharing has nothing to do woth it. Secure Channel is used by domain
member
computers to pass user authentication information to DCs.
2. There are companion settings "Digitally sign communications (always)"
and
"Digitally sign communications (when possible)" for both servers and
workstations. Set first to "Disabled" and second to "Enabled" and your
DCs
will communicate securely with users and insecurely with your printer.
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