North American Network Operators Group
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Re: Packet anonymity is the problem?

  • From: Patrick W.Gilmore
  • Date: Wed Apr 14 20:52:58 2004 
On Apr 10, 2004, at 10:48 PM, Sean Donelan wrote:
If you connect a dialup modem to the public switched telephone network, do
you rely on Caller ID for security? Or do you configure passwords on the
systems to prevent wardialers with blocked CLIDs from accessing your
system? Have a generation of firewalls and security practices distracted
us from the fundamental problem, insecure systems.


http://www.ecommercetimes.com/perl/story/security/33344.html
Gartner research vice president Richard Stiennon confirmed that packet
anonymity is a serious issue for Internet security.
[...]
"Because of the way TCP/IP works, it's an open network," Keromytis
said. "Other network technologies don't have that problem. They have
other issues, but only IP is subject to this difficulty with abuse."
Is IP really more insecure than, say, *nix? Back in the days of open mail relays and telnet and guest accounts and anonymous FTP sites, etc., hosts were at least as insecure as the "network" is today. Filtering source addresses is analogous to turning off telnet or applying TCP wrappers on a host. No one seems to think that securing your host is a bad idea, but securing your network seems to be way too much trouble.

Of course, the analogy only goes so far. Filtering source addresses costs you time & effort, and maybe even hardware if you are running old boxes. Not filtering doesn't really do much until someone launches an attack from your network and you might not even notice that. Leaving telnet running on your host hurts you directly, so that is not even considered.

Point is IP is not "inherently insecure". IP is just a transport mechanism. How you configure it, and what you do with it, is up to you.


[...]
Bellovin compared the situation to bank robberies. "[S]treets, highways
and getaway cars don't cause bank robberies, nor will redesigning them
solve the problem. The flaws are in the banks," he said. Similarly, most
security problems are due to buggy code, and changing the network will
not affect that.
I've always liked that Bellovin guy. :)

Another note: Today's attacks tend to not spoof source addresses. What's a few 10s of 1000s of zombies here or there? Let them be caught, not worth the time to put in source spoofing code. Easier to just make them spew massive bits as fast as they can. Shouldn't we concentrate on the problem (hosts), not the transport?

--
TTFN,
patrick