I am trying to block 80/443 on my server using iptables (prevent anyone from attempting to access the ports on the outside). The first rule I have for input is this:
I go to do a scan, and it returns, showing that ports 80 and 443 are open (TCP). Why are they still showing as open?

Paste the complete output of iptables -L, and are you sure the scan you're doing goes out of eth0?

Default policy is set to DROP.

Where and how do you do that scan. On the same server? The ports are not closed, the processes listening on the ports are still running.

You must run the test from the outside, going into Eth0.

For debugging, you can add a log entry. Note that log is non-terminating, so the traffic will continue after being logged.

jlinkels

I scan from the outside (the Internet) with nmap.

That is good. Then I am not sure IPTables will show the port as open while still denying a TCP connection. To be sure you can telnet into the port and see if you get "connection refused". Then you know the connection is denied.

And if you can connect, you should create that log entry to see if your rule matches.

You have a type here: -m tcp. In your second post it was corrected.

Since multiport is a module which is not installed by default (depending on your installation) try to skip the multiport and try a single port first. You can also create 2 rules. It is only 2 ports. Depending on how you enter the IPTables commands you might or might not see an error message on the multiport module.

jlinkels

I added this rule: -A INPUT -i eth0 -p tcp -m tcp --dport 80 -j DROP, but nmap still shows 80/tcp http.

-m tcp is not really needed. Although I believe it is correct, it is hardly specified explicitly.
You really should try this and see if something is logged:
Did you try the telnet connection as I suggested?

If the log does not show anything and telnet does connect, you make wrong assumptions somewhere. So install tcpdump and run:
while you telnet into your host.

It is plain impossible you see traffic on port 80 in tcpdump and you don't see anything in the log of IPTables.

jlinkels

So I've been thinking it might be better to just go to the root cause of the issue, and prevent apache2 from listening on the wan interface. I've modified ports.conf and sites-available/000-default.conf and default-ssl.conf, but a scan still shows the two ports. I'd rather not have to block them, and just have the product configured properly. Is there a configuration I'm missing somewhere, where the listening interface needs to be updated?

Have you changed the apache listen address to just your LAN?

Rules operate in order so while you just posted the one for port 80 you could have a something misplaced. In addition I prefer to set the default polices to drop then add rules to allow incoming traffic.

Now I asked you 3 times to add a log target to IPtables and to try a telnet connection from the outside to your box. And run tcpdump dependent on the previous outcome.

See, if you don't ever issue a test command you can keep trying things until you see blue in the face.

jlinkels

Yes.
My default policies are set to drop.

I will try this.

Added rules. It says it connected, and I saw a few results while running tcpdump.

Where are the logs?