RE: share permissions

["John Wright" <ineldorado () att net>]

----Original Message-----
From: listbounce () securityfocus com [mailto:listbounce () securityfocus com] On
Behalf Of Ansgar Wiechers
Sent: Tuesday, September 28, 2010 1:25 PM
To: security-basics () securityfocus com
Subject: Re: share permissions

On 2010-09-28 W W wrote:
> Are then any best practices for setting permissions on shared folders?
> We have a discussion on whether we should be setting the access on the
> share itself or controlling it more at the NTFS level.  I lean more to
> setting permissions on the share and at the NTFS level. Thoughts?

Common practice is to grant full access to everyone on the share level,
and restrict access on the NTFS level. If you are super mega hyper
paranoid, you can restrict share level permissions as well, but IMHO
that has more disadvantages than advantages. For one, troubleshooting
permissions becomes a pain when you have to deal with two sets of ACLs.
Also, share level permissions apply only to the share, while NTFS
permissions apply to the shared folder and all files and subfolders. Not
to mention that NTFS permissions are far more fine-grained than share
level permissions.

Regards
Ansgar Wiechers
-- 
"All vulnerabilities deserve a public fear period prior to patches
becoming available."
--Jason Coombs on Bugtraq

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I myself favor the super mega paranoid practice, but as an alterative to
setting smb permissions to everyone/full-access, you could give full access
to Authenticated Users, per the best practice suggestion in this article:
http://www.windowsecurity.com/articles/Share-Permissions.html


Incidentally, can anyone confirm that effective SMB permissions are an AND
operation (e.g. effective write permission only results when every group
specified in the ACL of which the user is a member has write permission)?

I know that the user should be a member of only one group specified in the
ACL for a share but, for curiosity's sake, I was hoping to find a definitive
reference confirming that this is exactly how SMB permission are calculated.
The dusty book on NTFS security that I've consulted is less specific on the
subject that I'd like.  Thanks for any help.

John




------------------------------------------------------------------------
Securing Apache Web Server with thawte Digital Certificate
In this guide we examine the importance of Apache-SSL and who needs an SSL certificate.  We look at how SSL works, how 
it benefits your company and how your customers can tell if a site is secure. You will find out how to test, purchase, 
install and use a thawte Digital Certificate on your Apache web server. Throughout, best practices for set-up are 
highlighted to help you ensure efficient ongoing management of your encryption keys and digital certificates.

http://www.dinclinx.com/Redirect.aspx?36;4175;25;1371;0;5;946;e13b6be442f727d1
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