Blocking SSH - Firewall Rule Troubles - SOLVED

tha_toadman · Feb 10, 2015, 8:42 PM

Ah, yep. Good point. I'll make the change and try again.

johnpoz · Feb 10, 2015, 8:46 PM

dude you should not have to put in any rules.. There is a default DENY!! Are you allowing traffic in like the OP?

if your going to block it has to be above your allow rule - post your rules.

If you have an allow for that segment, then above it put in a block to those specific addresses.

acherman · Feb 10, 2015, 8:48 PM

For me, I pretty much never put in a source port. As others have said, they are usually random, so no point. And also, I put them right at the top - since they are handled from the top down, start with the most specific and go from there.

acherman · Feb 10, 2015, 8:51 PM

My DMZ, or Public routed interface rules look like this now…

johnpoz · Feb 10, 2015, 8:55 PM

so anherman - are you rules in place to block it then? Cuz they are still open. 2 all 3 IPs.

So you have a 1:1 nat setup or something? Or your just routing the traffic?

acherman · Feb 10, 2015, 9:07 PM

Yup, those rules are active. No, no 1:1 set up at all. I do have some inbound stuff set up, but specific ports like 21, 80, 443, etc. Although I do have a couple that I have all ports forwarded to 3 customer devices, just because I don't know what ports they use - those are the ones noted in the middle of the WAN rules (noted as BCM access). But those are other IPs. Dumb question, how can I see what IP's they are trying to get authed on? My pfflowd packages aren't working, so I'm not sure how to look.

tha_toadman · Feb 10, 2015, 9:08 PM

For me, I pretty much never put in a source port. As others have said, they are usually random, so no point. And also, I put them right at the top - since they are handled from the top down, start with the most specific and go from there.

Yeah it was towards the end of the day when I put that original rule in. I've since modified it to read as:

block IPv4 TCP * * WAN address 22 (SSH) * none

I've corrected both the Floating and the WAN but I'm still telling you, SSH is open. The default deny isn't working in this case. Once that SSH server is enabled, it's WAN accessible on my box.

My top 3 rules on the WAN tab (apologies on the formatting):

block * Reserved/not assigned by IANA * * * * * * Block bogon networks
block * Private_Networks * * * * none (custom rule)
block IPv4 TCP * * WAN address 22 (SSH) * none Block SSH remote access

I don't have any 1:1 going either.

johnpoz · Feb 10, 2015, 9:15 PM

ok heres another thing - once you create the rules to block. You have to kill the states.. So for example got in.. You need to kill all the states from my IP, or flush them all. Or have to wait til they expire.

acherman · Feb 10, 2015, 9:20 PM

I actually added the rules, and then I turned SSH on and back to 22. Would that have not allowed the states to begin with? Or no?

johnpoz · Feb 10, 2015, 9:22 PM

no that would not have flushed the states in the firewall. That just tells the box to listen or not listen.

acherman · Feb 10, 2015, 9:27 PM

Okay, I just reset all states - that should confuse some people. I will watch the logs now…

johnpoz · Feb 10, 2015, 9:34 PM

so you do understand its not just ssh that is open

johnpoz · Feb 10, 2015, 9:35 PM

If you PM a login - I would be happy to take a look to what is going on.

And ssh is still open.. If you flushed the states.. You go something major issue here.. Either your rules are not being applied or you have something that in front of it allowing it.

pfctl -sa

Lets take a look at the rules..

acherman · Feb 10, 2015, 9:41 PM

PM sent. Thanks John.

Just joking. Apparently I hit the email button instead.

Derelict · Feb 10, 2015, 9:45 PM

I don't even know where to start with what's wrong with your rules. You might want to start over.

Of course everything is open. You are connecting to something on PUBLIC net. He has pass any any rules for that subnet from WAN1/WAN2.

johnpoz · Feb 10, 2015, 9:46 PM

Ok first thing I see is you have that allow any any rule on multiple interfaces.. So wan_shaw has any any to public net, and there is no blocks on that interface. So when I do a trace to that IP I hit..

13 49 ms 49 ms 47 ms 66.163.70.2
14 55 ms 52 ms 64 ms 64.141.125.254

What what connection is that 66.163.. So you have that allow on all your interfaces?

acherman · Feb 10, 2015, 9:51 PM

Looks like that 66.163.70.2 is the router on our Shaw WAN - the address that I hit there is 64.141.127.249.

johnpoz · Feb 10, 2015, 9:52 PM

Ok I put in a rule on your shaw wan to block ssh to your .250, 251, 254

And I it looks blocked now.

johnpoz · Feb 10, 2015, 9:55 PM

Ok I added logging to the rule, and you can see blocked from my attempt to all 3 of them

Your going to want to go through these connections and block services to pfsense interfaces. So for example I was able to remote in.. that should clearly be something you only allow when you want it.. And put in specific rule for ;)

acherman · Feb 10, 2015, 10:11 PM

Okay, so I had rules just like to start with (see first post). Weird. So, which address were you able to get in on?