multi-purpose server - security

Question

running ubuntu server 10.04. This box is both a web (apache2) and vpn (openvpn) server. Here is how the network is currently configured.

router 192.168.1.1
|
|
LAN
|
|
ubuntu server 192.168.1.2
NAS file serverA 192.168.1.3
NAS file serverB 192.168.1.4
20 workstations 192.168.1.50/70

Basic configuration, all workstations AND ubuntu server are behind router firewall. Port 80 for web server and 1200 for VPN server are forwarded from router to ubuntu server.

I've read how it's wise to put web server in DMZ, so if hacked, you can limit collateral damage and isolate your LAN from the attack. However, how would you do this on a multi-purpose server?

With multiple NIC's and 2 routers, could you do something like this?

router 192.168.1.1
|
|
LAN
|
|---WAN port----router 192.168.2.1
|                 |
|                 LAN
|                 |
|                 ubuntu server (apache2 nic) 192.168.2.2
|
ubuntu server (vpn nic) 192.168.1.2
NAS file serverA 192.168.1.3
NAS file serverB 192.168.1.4
20 workstations 192.168.1.50/70

any suggestions are appreciated!

Answer 1

The multiple routers / NICs design you have there won't do you any good if the same server is in both, and there isn't any kind of seperation between your system and apache. If the apache server gets compromised somehow, they have access to the system itself, which has access to the rest of the network via the other NIC.

You've got these two options:

1) Run apache inside a VM on the ubuntu server, and tie the VM's network to the DMZ'd NIC only.

2) Run apache on a separate machine that is only plugged into the DMZ.