Re: Disabling AS/400 File Access from Explorer -- MIDRANGE-L

Andrei,

S.A. Centea wrote:

> In our environment, any ordinary user can access from
> his NT 4.0 station all AS/400 files via Network
> Neighborhood - AS/400 - file structure system.
>
> This is a serious security gap for me, as it happens
> even for the weakest user.
>
> We are on OS/400 4.3 and CA 3.2.0.
>
> Does anybody know how can I disable this access?

Your network has just pointed out the shortcomings of traditional AS/400 
Security
designs.  Too many AS/400 applications rely on menu systems to secure access to
the data, but Network Neighborhood doesn't know about your Menu system and will
never learn to respect it.  For the complete version of this answer I'll be
speaking to the Chicago AS/400 user group http://www.omniuser.org/ this coming
Tuesday evening on this very topic, so if you are in the Chicago area stop by 
and
say Hi!

Now for the abbreviated version...
This is a well known problem, and there are a couple of solutions.   The first
(and least desirable) is to use the authorization list QPWFSERVER to disable
*PUBLIC's ability to see the AS/400's QSYS.LIB via Network Neighborhood.   But
frankly this approach is full of problems.   The first is that it only "hides"
access through Network Neighborhood, and doesn't protect you from FTP, Remote
Command, ODBC and other SQL accesses.  If someone can see Libraries and files
through Network Neighborhood, they will certainly be able to see them through 
all
of the other data access methods that the AS/400 supports.  Worse still, if the
user has *CHANGE or *ALL rights to the files, they can really do damage.

Another problem is that QPWFSERVER can completely disable other useful functions
such as Netserver printing etc.  I published a technical tip in News/400 in
December on this topic, and in April got blasted by a reader who implemented
QPWFSERVER and found that it diabled all of her shared printers. Yikes!

Another approach is to modify your user's authority to the underlying AS/400
objects.   Many would argue that this is best way to fix the problem,  and they
would be right if you actually had the time and the resources to re-examine your
applications to use resource security.  This approach is made even more 
difficult
if you're security nightmare was inflicted on you by your application vendor...
because they problably don't know how to fix their own system, and will
re-inflict their scheme on you with each new release.

The third solution is to use OS/400 exit points to regulate network data
requests.  We have a product called PowerLock that was built specifically around
this approach.  By posting programs at the exit points you can regulate who will
have access via all of the different servers and reject requests that compromise
your AS/400 data.  If you want to know more about PowerLock, you can visit our
web site at www.400security.com

But in any case, if you're in Sara Lee's Chicago office, do come by the Omni 
User
Group's meeting this Tuesday night.   It won't be a product pitch, but it will 
be
highly informative.


jte


--
John Earl   johnearl@toolnet.com

PowerTech Toolworks  206-575-0711
PowerLock Network Security www.toolnet.com
The 400 School   www.400school.com
--


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