full-disclosure - How to easily bypass a firewall...

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From: avalon at caligula.anu.edu.au (Darren Reed)
Subject: How to easily bypass a firewall...

In some mail from Schmehl, Paul L, sie said:
> 
> If I break in to a Linux box, for example, all I have to do, once I have
> root, is type:
> % /etc/rc.d/init.d/ipchains stop
> 
> If it's a Windows box, I just kill the service:
> C:\ sc stop {firewall servicename}
> 
> Or install the pstools to do it.
> 
> The point is, once the box is owned, nothing else matters.

Whereas if they were using, say, NetBSD with IPFilter and turned
the securelevel to be >= 2, you cannot turn off or otherwise change
ipf's configuration without a reboot.

Of course this then leads back to the problem of having all the
requisite bootup files immutable to prevent trojan'ing and that
can make things harder to administer than it is worth the effort.

Darren