[isapros] Re: FW: FWENGMON issue for the brain trust
- From: "Young, Gerald G" <Gerald.Young@xxxxxxxxxx>
- To: <isapros@xxxxxxxxxxxxx>
- Date: Fri, 7 Jul 2006 09:03:59 -0500
Hmmm...
I'm afraid to voice my opinion because I certainly don't want to be
shunned but...
Would it be that hard to add the event log and auditing features to the
tool or the APIs? I mean, that would be an "improvement", wouldn't it?
And there are different levels of abuse this tool or APIs could
potentially allow. Suppose an unethical admin out there used it to
create a bypass to a questionable website or something. Does the bypass
mean that ISA wouldn't even log the traffic? Or, reverse that and
suppose the unethical admin is working with an outside source and he
creates an incoming bypass. If you can't see the bypass, chances are
inbound traffic won't be noticed unless it's pervasive or something else
brings attention back to the firewall.
And keep in mind that someone could create another utility that makes
use of those APIs by playing with ISA on their own and then publish that
utility once they figure out what those APIs are.
In my opinion, if adding that functionality to the tool or APIs helps to
minimize those kinds of risks, it makes sense to me to add it.
Cordially yours,
Jerry G. Young II
MCSE (4.0/W2K)
Atlanta EES Implementation Team Lead
ECNS Microsoft Engineering
Unisys
11493 Sunset Hills Rd.
Reston, VA 20190
Office: 703-579-2727
Cell: 703-625-1468
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________________________________
From: isapros-bounce@xxxxxxxxxxxxx [mailto:isapros-bounce@xxxxxxxxxxxxx]
On Behalf Of Jim Harrison
Sent: Friday, July 07, 2006 1:12 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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