Security Basics: Re: Attacking a machine on network.

[Paul Sebastian Ziegler <psz () observed de>]

> If someone doesn't run a service, this obviously leads me to the
> assumption that that particular machine could never be cracked ? Is this
> a right assumption ?
Not really. Some attacks actually target the drivers of the
network-interfaces. For example the WLAN drivers on MacOS X and some
versions of Madwifi had issues. Since those drivers listen to the
traffic anyway, it might be possible to trigger some sort of overflow
without a single listening port.
Also information leakage may occur no matter if the box is running any
ports itself.
Furthermore there are other techniques to communicate with boxes than
just ports. Look up "portknocking" for that.

My two cents
Paul