[isapros] Re: FW: FWENGMON issue for the brain trust
- From: "Thomas W Shinder" <tshinder@xxxxxxxxxxx>
- To: <isapros@xxxxxxxxxxxxx>
- Date: Fri, 7 Jul 2006 10:09:35 -0500
Hey Jim,
That's what I was thinking. The problem is this guy is a real ISA
firewall fan, but he shows this feature to customers who for some
reasons get their undies in a bunch and think that because of this the
ISA firewall is not as secure as the promethean "hardware" firewalls
that get hacked, whacked and attacked sucessfully on a daily basis. I'll
let you know who it is out of band.
Tom
Thomas W Shinder, M.D.
Site: www.isaserver.org <http://www.isaserver.org/>
Blog: http://blogs.isaserver.org/shinder/
Book: http://tinyurl.com/3xqb7 <http://tinyurl.com/3xqb7>
MVP -- ISA Firewalls
________________________________
From: isapros-bounce@xxxxxxxxxxxxx
[mailto:isapros-bounce@xxxxxxxxxxxxx] On Behalf Of Jim Harrison
Sent: Friday, July 07, 2006 12:12 AM
To: isapros@xxxxxxxxxxxxx
Subject: RE: [isapros] FW: FWENGMON issue for the brain trust
I do, but Danny made me wait until I stopped spitting
expletives.
I agree with message #2 - if the app isn't there, the
functionality isn't available.
Granted, the Mark Russonovich's or Tim Mullens could probably
sniff out the APIs and create all manner of H&D, but so what - anyone of
that skill level that has direct local-admin access to your box just got
themselves a free server anyway.
If the app isn't left on the box and the attacker doesn't have
local-logon, admin rights (oh damn; game over), then WTF cares what APIs
may exist that you can't get to without prior knowledge (and
not-insignificant programming skills) or a product-team-provided
debugging tool? IOW, if they're all that worried about who can do what
when they log onto the ISA locally as an ISA admin, they've already lost
the war.
This guy has way too much time on his hands if this is the sort
of thing he gets wound up about. Was this Andy?
We now return you to your regularly scheduled profanity-filled
retorts.
________________________________
From: isapros-bounce@xxxxxxxxxxxxx on behalf of Thomas W Shinder
Sent: Thu 7/6/2006 2:22 PM
To: isapros@xxxxxxxxxxxxx
Subject: [isapros] FW: FWENGMON issue for the brain trust
No one gots no opinion on this one?
-----Original Message-----
From: isapros-bounce@xxxxxxxxxxxxx
[mailto:isapros-bounce@xxxxxxxxxxxxx]
On Behalf Of Thomas W Shinder
Sent: Wednesday, July 05, 2006 9:10 PM
To: isapros@xxxxxxxxxxxxx
Subject: [isapros] FWENGMON issue for the brain trust
Hey folks,
There was a discussion on the beta newsgroup that I thought
would be
interesting to put in front of the brain trust. There's nothing
NDA
here, so it's cool. My impression is that the person who was
concerned
about the fwengmon /allow option is akin to the IPv6 issue -- if
the
admin is incompetent, malicious or both, then of course the
fwengmon
/all option can be abused. But the same incompetent and
malicious admins
can hork any other kind of firewall.
The example of the SBSer reading e-mail on the box is
archetypal
for the idiot admin who goes out of his way to subvert firewall
security, so how is this different from creating an "allow all
from
everyone to everywhere" which you can do on any firewall,
including the
ISA firewall?
Wondering if customers really need to get their undies
in a
bunch about this or its is calling "fire" at a weenie roast?
===========================
Message 1:
In my personal opinion, the interface method which "fwengmon.exe
/allow"
calls should not exist; there should be no such
bypass-the-firewall
method,
even if it is handy for troubleshooting.
If it can't be removed, then there should at least be an Event
Log
message
whenever it's invoked, and the fwengmon.exe tool should be able
to
display
whether or not there are any bypasses currently configured so
that it
can be
audited (the "/noallow" switch will turn any bypasses off, but
it
doesn't
indicate whether it did anything or what the IP addresses were
in the
cancelled bypass).
I'm sure the ISA development team uses the bypass feature
constantly,
but
that's development/debug code, and it wouldn't have to exist
when the
final
product ships. Whenever I show others the "/allow" switch and
its
invisibility of operation, the response is always very negative.
Message 2:
Yes, but you have to get the file on the box. If I can place
files on
the
firewall without your knowledge, the game is already over, isn't
it?
Message 3:
I agree it's a bit paranoid, but I think the even greater threat
comes
from
external buffer overflow attacks that call that method or
malware that
does
the same when invoked by an interactively-logged on
administrator who
browses the net or reads e-mail as admin while at the ISA box
(which
will
probably be running SBS, yet it will be ISA that gets the blame
for it
when
the vulnerability is published). In these cases, fwengmon.exe
wouldn't
even
have to be on the local drive. At a minimum, it would be nice
if
invoking
that method --whatever it is-- at least wrote a message to an
Event Log.
(I
also don't like how "lockdown mode" does not drop all existing
connections
and still allows new outbound connections, but that's another
story and
easy
enough to fix with a custom panic script.)
On a purely marketing level, too, ISA has lots of prejudice to
overcome,
so
I've encountered anti-Microsoft sysadmins who jump all over this
"invisible
hole feature" to undermine ISA as a trustworthy firewall (and
then this
can
sway the fence-sitters in the room to lean to the negative
side). I'd
still
prefer it if this firewall-bypass functionality didn't exist at
all...
======================
Thomas W Shinder, M.D.
Site: www.isaserver.org <http://www.isaserver.org/>
Blog: http://blogs.isaserver.org/shinder/
Book: http://tinyurl.com/3xqb7 <http://tinyurl.com/3xqb7>
MVP -- ISA Firewalls
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