Full Disclosure mailing list archives

Counseling not to use Windows (was Re: Anonymous surfing my ass\!)


From: full-disclosure () lists netsys com (David F. Skoll)
Date: Mon, 15 Jul 2002 15:10:12 -0400 (EDT)

On Mon, 15 Jul 2002, Roland Postle wrote:

because of programming errors.  Encoding metadata such as "executableness"
in a filename, for example, is a fundamental design flaw, and one that's
impossible to correct without changing Windows' design.

Sorry to pick on your example but an extension merly indicates what kind of
data is in the file.

Not under Windows as it is configured by 99.99% of end-users.  If you
name a file "foo.txt", very different things happen if you click on the
file than if you click on the exact same file named "foo.exe".

A .txt extension suggests that a user might want to
hand the file to a program that'll treat the file as plain ASCII, similarly
an .exe extension suggests that a user might want to give the file some
memory and time slices and treat it as a program in it's own right. You
could load the .exe into notepad, and you could execute the .txt file.

Again, for 99.99% of end users, such fine points are irrelevant.  To them,
clicking on an .exe runs the program.  Windows even "helpfully" hides the
extension by default.

As for the actual security of whether a user /can/ execute a file, Windows
doesn't seperate 'read' and 'execute' privileges well enough. However it's
my understanding that's got more to do with the design of the x86 memory
architecture than Windows' design. Linux just pretends to seperate 'r' and
'x' privs because it's a unix clone. I'm prepared to stand corrected on that
though.

That is true when it comes to memory protection, but what you're
talking about is filesystem protection, and Linux doesn't "pretend"
anything -- it enforces it.  I believe it is possible under some
versions of Windows to allow read access but not execute access to
files and directories, but again, 99% of end-users don't know this
and don't configure it.

I agree completly that Windows does have some fundamental design flaws that
prevent it being locally secure. A better example might be the ability of an
application to send messages to another application, apparently without
regard for who the owner of the target application is.

:-)  I'm not familiar enough with Windows to be aware of things like that.
Thanks.

Regards,

David.



Current thread: