[lamour () mail argfrp us uu net: Fwd: Re: If you have nothing to hide]

[Todd MacDermid <tmacd () synacklabs net>]

In message <20020805225221.82473.qmail () sidehack sat gweep net>, bdragon@gweep.n
et writes:
> I was not aware that responses to source-routed packets were themselves
> source-routed. I also don't believe it is the case, but am open to being
> contradicted. If the responses aren't source-routed, then the packets would
> only return through your network if your network was the path back to the
> spoofed source.

A friend of mine directed me to this thread. Source routed packets
can indeed be used to spoof IP connections, and I've written a tool
to do it. It's available at http://www.synacklabs.net/projects/lsrtunnel

If you simply want to check host behaviour to see if you can spoof
connections, I've written a scanner at
http://www.synacklabs.net/projects/lsrscan

Short story is Solaris < 8 will reverse source routes by default, and
Windows boxes will reverse source routes by default. The BSDs and
Linuces I've tested mostly block source routed packets by default.

Todd