Re: [fw-wiz] Question about setting up PIX firewall



On Fri, 2 Dec 2005, James wrote:

> I would strongly disagree Paul. We can learn an enormous amount of
> recon intelligence from Matthews config.
>

Well, I got several messages of support which said "I'm glad you said that
so I didn't have to (those folks are welcome to chime back in,) so let's
look at your points..."

> 1. We know he is using a PIX so we only have to look for exploits for that.

Assuming it's up to date, that leaves zero day explioits, which really
should be rare these days. It also assumes the PIX is the only
firewall there (which is likely, but not definite.)

> 2. Domain name-> domain-name spectrumdirect.local and dns server
> vpngroup SpectrumDirect dns-server 192.168.1.250
> 192.168.1.250
>

Yes, we could probably derrive that anyway- it's a .edu- it's not like
their architecture is uber seekrit...

> 3. His rfc1918 subnet-> 192.168.1.128 255.255.255.128
> Which we may be able to exploit with source routed packet attacks.
> (I am not sure how well the PIX stands up to these)

If either strict or lose sorce routing gets through your firewall, it's a
decade out of date... In any case, *lots* of people use outlook express
or other things which "leak" 1918 addresses, that shouldn't matter one
bit. Know what? My home network is 10.1.10.x/24- knowing that won't do
you one bit of good, because my security implementation is as strong as
it needs to be and my ruleset is protective..

>
> 3.He is using a client to site vpn with split tunnellling enabled so if we could
> find a users home PC and compromise it we could gain a significant
> amount of access while the user is connected to the vpn.
>

But if you could find a client *and* compromise it, you'd be able to do
that *anyway*, knowing the ruleset doesn't signifcantly change the risk
there. FWIW, you'd have to find and compromise a VPN-allowed client and
if you can do that, there are way more useful things you can do as an
attacker with or without split tunneling. If you need split tunnnels,
you're likely not sophisticated enough an attacker to worry about the
minor incremental risk.

> 4. We know the vpn config so we can easily get our hands on the cisco vpn client
> and try to BF the password because the AUTH is LOCAL and the BF
> attempt probably won't be detected.

If it's subject to a brute force, it is anyway- it's more likely that that
would happen blind these days.

>
> 5. telnet 192.168.1.0 255.255.255.0 inside
> Telnet is used to administer the box so if we can compromise the web
> server inside we can
> probably sniff the pix passsword and allow ourselves whatever access we want.

If you could do that, you'd be able to do the same thing anyway, the
confing doesn't materially add to that- you'd still have to have an
exploit. Of course, this assumes the network is sniffable, which is not a
given these days. On a .edu network, an outside attacker isn't the likely
point of compromise anyway.

> These are just a few ideas I pulled of the top of my head. Matthew
> Davis if you are reading this I strongly adivse you to request the
> firewall wizards mailing list pull your post off their servers and
> also request google to do the same however more than likely your post
> has
> allready been cached and or skimmed.

Assuming your firewall is functional (and you've provided zero evidence
that his isn't) then if your firewall ruleset isn't publically auditable,
you're doing something wrong. If it is, then its disclosure adds very
little to the actual risk.

Paul
-----------------------------------------------------------------------------
Paul D. Robertson "My statements in this message are personal opinions
paul@xxxxxxxxxxxx which may have no basis whatsoever in fact."
http://fora.compuwar.net Infosec discussion boards

_______________________________________________
firewall-wizards mailing list
firewall-wizards@xxxxxxxxxxxxxxxxxx
http://honor.icsalabs.com/mailman/listinfo/firewall-wizards



Relevant Pages

  • RE: Sandboxing
    ... the 3Com Embedded Firewall would be extremely useful and enabling (in ... your case) when you look at it in a VPN context. ... This security policy will accomplish quite a few things: ... During the Policy Server installation, ...
    (Focus-IDS)
  • Re: VPN Firewall for new webserver
    ... > I'm setting up a webserver at a colocation and I need to put a VPN ... You're not going to get a quality firewall for that amount, ... and D-Link makes a DI-804HV unit ... users access to the SQL server, let them do it through a VPN session. ...
    (comp.security.firewalls)
  • Re: Firewall Info/Recommendations?
    ... I would seriously consider an air-gap solution. ... Let me outline a few features that no other firewall can touch. ... Provide secure access without a VPN from any web browser (this greatly ... > manageable without much higher-level support if you want things like ...
    (comp.security.firewalls)
  • Re: [fw-wiz] Integrated IDS/IPS/Firewall (Cisco ASA and Juniper ISG)
    ... complexity and architectural inelegance of having 3-5 gateway security ... VPN) convinced me to eventually champion a migration to Symantec's SGS ... Nice balance of "default deny" at the firewall, ...
    (Firewall-Wizards)
  • Re: two winxp home machines, varied results
    ... >The only firewall I have on my machine *aside* from the Cisco VPN ... Please don't change "restrictAnonymoussam", only ... >Here is the IPCONFIG and BROWSTAT listings for each machine. ...
    (microsoft.public.windowsxp.network_web)