H,
If I had a network behind a firewall, do I need to lock down services available on the inside?
I've seen recently where some people trust their firewalls that much that they have linux installed on machines with ftp, telnet, even sendmail and just about everything else listening.
Is that a bad thing?
Your thoughts on this would be appreciated. Sorry, no problems for you all to get your teeth into :-)
Regards.

IMO i don't think it's *that* big of a risk. linux by default is pretty secure with just the standard settings (sendmail, ftp, etc) listening. although, if you're on an internal network, i see no reason to leave FTP, telnet, and possibly sendmail - depending on your config - listening. so disabling those would increase security, and not sacrifice functionality.

personally, i leave pretty much everything open behind my firewall - save FTP - since my firewall has been able to do the trick, and that aside from sendmail, everything is pretty secure anyways.

the only security issue i have is i leave telnet open on my firewall, since at work i operate behind a real strict firewall, and i can't punch an ssh connection through, but i can with telnet. so it's the only way i can get through to my network at home.

Anyone?

How about inside threats? Some compromised box is sniffing your main box?

IMO, every service/server should be turned off at boot. Some distro lets you deselect them at install. It's the first thing I do: locking the box down.

Yes, it show's they haven't got a basic grasp on securing boxen. By default you should only enable the services you *need*, even on a LAN, unless you've got a strict trust relationship with all boxen. Disabling/de-installing unnecessary services saves time on securing, maintenance and IDS checking, CPU power, reduces possible risks and when another box on the LAN is broken into won't have your box for lunch.

Thanks guys. The chance of internal threats is quite high in the case I mentioned. I should lockdown the box for them! But they seem to "know" what they are doing. The stupid thing is, they already had a compromised TACACs server once! Set up by a Cisco CCIE no less!

Thought youd like a laugh on a Monday morning.

Cheers.