Linux Labs

Server security / Stage 1 of 10

Auditing listening services

Not running Starting usually ~20 s
Leave the lesson

Step 5 of 7 · on a machine · 4 min

The admin panel behind the filter

Now a filter for this server: its admin panel has no address setting. The check is again from the outside machine.

The admin panel is used only on the server itself: the administrator logs in over SSH and opens it there. Build your ruleset from the inventory in the second step — the entrances the server goes on the internet for stay open outside. In this exercise the database already listens on localhost only, so the panel is the only extra thing left outside.

Exercise · do it

Put the admin panel behind the filter

The lab-admin practice panel listens on 0.0.0.0:8080, and its address cannot be configured. Close it to the outside machine with an nftables filter that also loads after a reboot. SSH and the site must stay reachable from outside, and the panel on the server itself: curl -s http://127.0.0.1:8080/.

Sign in and start The machine is available after signing in

Goals · 0 of 3

  • Close the panel to the outside machine not done yet
  • Keep SSH and the site open outside, and the panel on the server itself not done yet
  • Keep the filter for the next boot not done yet

Step goals

0 of 3
  • Close the panel to the outside machine — not done yet
  • Keep SSH and the site open outside, and the panel on the server itself — not done yet
  • Keep the filter for the next boot — not done yet
Ubuntu 24.04

Step goals

0 of 3
  • Close the panel to the outside machine — not done yet
  • Keep SSH and the site open outside, and the panel on the server itself — not done yet
  • Keep the filter for the next boot — not done yet
Loading…