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    2.1 Failing the GRC firewall test

    Scheduled Pinned Locked Moved General pfSense Questions
    47 Posts 13 Posters 14.9k Views
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    • stephenw10S
      stephenw10 Netgate Administrator
      last edited by

      @johnpoz:

      what would be requesting those privileged ports??

      A virus? I can't think what else could possibly need 627 ports.
      UPnP isn't enabled by default though, at least you have to be vaguely aware of the consequences before enabling it. UPnP seems to cover a lot these days though. Although pfSense only implements the port forwarding parts of it I get the impression a lot of people enable it thinking it will help them with DLNA device discovery. It won't.

      Steve

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      • johnpozJ
        johnpoz LAYER 8 Global Moderator
        last edited by

        Even a virus would not need 627 ports ;)  While not saying its not UPnP, I would look to something a bit more general in nature like device in front of pfsense.. ISP doing something?  Just plain something broke in GRC?.  Have you tried another scanner? Seem unlikely even that a virus would open 627 ports if you ask me..

        A 10 second sniff on your wan port would tell you if this traffic is even getting to pfsense and if pfsense or something behind it is answering, etc.

        An intelligent man is sometimes forced to be drunk to spend time with his fools
        If you get confused: Listen to the Music Play
        Please don't Chat/PM me for help, unless mod related
        SG-4860 24.11 | Lab VMs 2.7.2, 24.11

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        • H
          Harvy66
          last edited by

          I've had odd  results with the GRC scan. I'm not sure where some of the "closed" responses are coming from, but when I look at my PFSense logs, the ports that show "stealth" on GRC, show a logged event in PFSense, but the ports that show "closed" in GRC, do not show in my PFSense logs. Something else up-stream is responding. The only ports I get as "closed" are related to SMB. I assume my ISP is blocking remote SMB on their firewall.

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          • KOMK
            KOM
            last edited by

            0-1055 all stealth here.

            1 Reply Last reply Reply Quote 0
            • stephenw10S
              stephenw10 Netgate Administrator
              last edited by

              @johnpoz:

              Even a virus would not need 627 ports ;)

              Yeah, not exactly stealth. Worst. Virus. Ever.  ::)

              Seems more likely to be not actually scanning pfSense for whatever reason. CG-NAT perhaps?

              Steve

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              • K
                kejianshi
                last edited by

                I actually believe those results could be true.

                Post an IP.  I can scan it from here.  I'm sure a few of us could confirm if the results are good or not.

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                • H
                  Harvy66
                  last edited by

                  @kejianshi:

                  My thoughts exactly.  uPNP may be forwarding  (opening) ports you have not thought about.

                  This is why I put int an explicit block on ports 1-1023. I don't want any pesky uPNP trying to do strange things.

                  The biggest issue isn't uPNP, it's that I need to use NAT in the first place. Many games need to listen on ports, but because you can't have multiple clients all using the same ports, you can't know which ports will be used ahead of time. If port opening needs to be dynamically controlled by the client, how else does one handle this?

                  My main concern isn't what my clients are trying to do, it's what the public Internet is trying to do to my clients. As long as standard service ports are not opened, I'm content. Home install, I'm not a network admin.

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                  • johnpozJ
                    johnpoz LAYER 8 Global Moderator
                    last edited by

                    No the issue is how UPnP is implemented without any security/auth that allows something to be opened, and ease of control of what that device can open, etc.  Most home routers give you no control at all.

                    Not sure what your blocking - but inbound from the wan has all ports block out of the gate.  Where are you creating this 1-1023 block?

                    While its true many ports need to listen on port - they sure shouldn't be < than 1023..  Where in the list of ports are there any games that have these ports registered?

                    http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.txt

                    I don't see any games?  No game that I could think of should be listening on a PRIVILEGED port that is for sure..

                    There is a SHIT load of ports to be used - how many games are you running that it should ever overlap, and people that design a game that is played over the internet and don't take into account the ability to control which ports are used are just not thinking if you ask me!!

                    I have never ran into such a game.  All the issues go away soon with NAT you can hope as IPv6 is here - With lots of IPs to play with that removes the need of nat completely.  These games still do not need to listen on ports < 1023..  So from his listing 416 to 557 are OPEN..  Why would something open such a big range privileged..  If we look up those ports.

                    example
                    nnsp                433        tcp    NNSP

                    This is port used for bulk transfers of NNTP between servers..  Why would some GAME use that port?  And since its under 1023 should require elveated permissions to even listen on that port, etc.

                    If I ran across a scan showing such results - the first thing I would do is run the scan again while sniffing on wan and validate for starters that scan is actually hitting my IP and that responses are leaving my interface because its so out there it is highly unlikely there is anything actually listening on all those ports to have it show "OPEN"

                    An intelligent man is sometimes forced to be drunk to spend time with his fools
                    If you get confused: Listen to the Music Play
                    Please don't Chat/PM me for help, unless mod related
                    SG-4860 24.11 | Lab VMs 2.7.2, 24.11

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                    • K
                      kejianshi
                      last edited by

                      When you put in your block rules, are you rejecting with some message or dropping packets silently?

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                      • H
                        Harvy66
                        last edited by

                        @kejianshi:

                        When you put in your block rules, are you rejecting with some message or dropping packets silently?

                        Always drop, not reject.

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                        • K
                          kejianshi
                          last edited by

                          Yep - Thats why I'm asking.

                          1 Reply Last reply Reply Quote 0
                          • S
                            Supermule Banned
                            last edited by

                            80.197.155.13

                            @kejianshi:

                            I actually believe those results could be true.

                            Post an IP.  I can scan it from here.  I'm sure a few of us could confirm if the results are good or not.

                            1 Reply Last reply Reply Quote 0
                            • H
                              Harvy66
                              last edited by

                              @johnpoz:

                              No the issue is how UPnP is implemented without any security/auth that allows something to be opened, and ease of control of what that device can open, etc.  Most home routers give you no control at all.

                              Not sure what your blocking - but inbound from the wan has all ports block out of the gate.  Where are you creating this 1-1023 block?

                              While its true many ports need to listen on port - they sure shouldn't be < than 1023..  Where in the list of ports are there any games that have these ports registered?

                              http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.txt

                              I don't see any games?  No game that I could think of should be listening on a PRIVILEGED port that is for sure..

                              There is a SHIT load of ports to be used - how many games are you running that it should ever overlap, and people that design a game that is played over the internet and don't take into account the ability to control which ports are used are just not thinking if you ask me!!

                              I have never ran into such a game.  All the issues go away soon with NAT you can hope as IPv6 is here - With lots of IPs to play with that removes the need of nat completely.  These games still do not need to listen on ports < 1023..  So from his listing 416 to 557 are OPEN..  Why would something open such a big range privileged..  If we look up those ports.

                              example
                              nnsp                433        tcp    NNSP

                              This is port used for bulk transfers of NNTP between servers..  Why would some GAME use that port?  And since its under 1023 should require elveated permissions to even listen on that port, etc.

                              If I ran across a scan showing such results - the first thing I would do is run the scan again while sniffing on wan and validate for starters that scan is actually hitting my IP and that responses are leaving my interface because its so out there it is highly unlikely there is anything actually listening on all those ports to have it show "OPEN"

                              "Where are you creating this 1-1023 block?"
                              On the WAN interface. I assume the firewall rules take precedence over the uPNP, but I could be wrong. If I am wrong, then uPNP could effectively bypass the firewall in an uncontrollable way.

                              "I don't see any games?"
                              I never said any games use those ports. Me blocking service ports only has to do with being paranoid about uPNP, assuming the block actually works against uPNP.

                              "There is a SHIT load of ports to be used - how many games are you running that it should ever overlap"
                              Running the same game on two different computers will run you into trouble if the game requires a specific port to be forwarded. How can you forward the same port to two different computers, especially if the same two computers are trying to communicate with the same servers? You can't. Many of these games require uPNP in order to use non-standard ports. Not to mention micromanaging port forwarding and messing with game configurations when you friends come over is a huge headache. Assuming the games even give you the option to manually change your ports. Most dynamically choose a port at run time, and if that port isn't being forwarded, you can't play.

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                              • K
                                kejianshi
                                last edited by

                                Supermule - Running a scan - Although, seems more likely thats your server…

                                Its abit slow.  Taking its time.

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                                • S
                                  Supermule Banned
                                  last edited by

                                  :D Its my homenetwork guarded by pfSense and some other gimmicks :D

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                                  • S
                                    Supermule Banned
                                    last edited by

                                    Is 77.66.122.109 your IP?

                                    @kejianshi:

                                    Supermule - Running a scan - Although, seems more likely thats your server…

                                    Its abit slow.  Taking its time.

                                    1 Reply Last reply Reply Quote 0
                                    • K
                                      kejianshi
                                      last edited by

                                      Yeah - I'm into your porn now…  (kidding)
                                      Still running.  I'll post the results, although I'm sure the results will be next to nothing.

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                                      • S
                                        Supermule Banned
                                        last edited by

                                        Are you located in Copenhagen or just hooking up on some VPN??

                                        IP address: 77.66.122.109
                                        Reverse DNS: No Reverse DNS found
                                        Reverse DNS Authenticity: Unknown
                                        ISP: Netgroup A/s
                                        Country: Denmark Denmark
                                        CountryCode: DK
                                        Region: Hovedstaden
                                        City: Copenhagen
                                        Private IP: No

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                                        • K
                                          kejianshi
                                          last edited by

                                          I'm in Manilla…
                                          That VM is running on a machine is in a rack in Copenhagen. 
                                          I did use a VPN to access the desktop and kick off the scan, but I'm not in the desktop right now.
                                          Looks like it will take about another 20 minutes.  Abit like watching paint dry.
                                          I'll check it again in 20.

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                                          • K
                                            kejianshi
                                            last edited by

                                            All scanned port filtered.  Also doesn't respond to ping.

                                            In other words, less than nothing.

                                            I only scanned 2000 ports.

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