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    DDoS attacks OpenVPN on Pfsense

    Scheduled Pinned Locked Moved Firewalling
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    • KOMK
      KOM
      last edited by

      I don't understand. I've been running OpenVPN for years now, and I've never had any ghost connections tying everything up. I'm being scanned and probed just as much as everyone else. Nothing ever connects to it except for valid users. Does this happen to anyone else? In all my years here, I've never heard of a similar complaint. Is this actually a real problem?

      L GertjanG 2 Replies Last reply Reply Quote 0
      • johnpozJ
        johnpoz LAYER 8 Global Moderator
        last edited by

        I have never see bogus hits on openvpn tie up a connection no..

        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 2.8, 24.11

        1 Reply Last reply Reply Quote 0
        • L
          leungda @KOM
          last edited by

          @kom

          I can say you are lucky

          1 Reply Last reply Reply Quote 0
          • DerelictD
            Derelict LAYER 8 Netgate @netblues
            last edited by

            @netblues said in DDoS attacks OpenVPN on Pfsense:

            Are you using a static tls key?

            Are you using a static TLS key? How is your server configured?

            Chattanooga, Tennessee, USA
            A comprehensive network diagram is worth 10,000 words and 15 conference calls.
            DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
            Do Not Chat For Help! NO_WAN_EGRESS(TM)

            1 Reply Last reply Reply Quote 0
            • GertjanG
              Gertjan @KOM
              last edited by

              @kom said in DDoS attacks OpenVPN on Pfsense:

              Does this happen to anyone else?

              #Metoo.
              Having a static IPv4 your years now, but never saw something like that.
              TLS Keys : of course, I use these.

              No "help me" PM's please. Use the forum, the community will thank you.
              Edit : and where are the logs ??

              1 Reply Last reply Reply Quote 0
              • L
                leungda
                last edited by leungda

                two different sites got attacked. They are different client and network. They got attacked with the same IP address.

                How can i extract OpenVPN log from pfsense

                1 Reply Last reply Reply Quote 0
                • NogBadTheBadN
                  NogBadTheBad @leungda
                  last edited by

                  @leungda

                  Whats the IP address, it's not comming from shodan or shadowserver is it ?

                  I get these almost every day poking my IPsec VPN, create a blacklist in snort if it is.

                  shadowserver:-
                  
                  216.218.206.0/24
                  
                  shodan:-
                  
                  198.20.69.72/29		# census1.shodan.io
                  198.20.69.96/29		# census2.shodan.io
                  198.20.70.112/29	# census3.shodan.io
                  198.20.99.128/29	# census4.shodan.io
                  93.120.27.62		# census5.shodan.io
                  66.240.236.119		# census6.shodan.io
                  71.6.135.131		# census7.shodan.io
                  66.240.192.138		# census8.shodan.io
                  71.6.167.142		# census9.shodan.io
                  82.221.105.6		# census10.shodan.io
                  82.221.105.7		# census11.shodan.io
                  71.6.165.200		# census12.shodan.io
                  188.138.9.50		# atlantic.census.shodan.io
                  85.25.103.50		# pacific.census.shodan.io
                  85.25.43.94			# rim.census.shodan.io
                  71.6.146.185		# pirate.census.shodan.io
                  71.6.146.186		# inspire.census.shodan.io
                  71.6.158.166		# ninja.census.shodan.io
                  198.20.87.96/29		# border.census.shodan.io
                  66.240.219.146		# burger.census.shodan.io
                  209.126.110.38		# atlantic.dns.shodan.io
                  104.236.198.48		# blog.shodan.io
                  104.131.0.69		# hello.data.shodan.io
                  162.159.244.38		# www.shodan.io
                  159.203.176.62		# ny.private.shodan.io
                  188.138.1.119		# atlantic249.serverprofi24.com
                  80.82.77.33		# sky.census.shodan.io
                  80.82.77.139		# dojo.census.shodan.io
                  71.6.146.130		# ubtuntu16146130.aspadmin.com
                  66.240.205.34		# shodan.io
                  216.117.2.180		# malware-hunter.census.shodan.io
                  93.174.95.106		# battery.census.shodan.io
                  89.248.172.16		# house.census.shodan.io
                  185.163.109.66		# goldfish.census.shodan.io
                  93.174.95.106		# battery.census.shodan.io
                  89.248.167.131		# mason.census.shodan.io
                  94.102.49.190		# flower.census.shodan.io
                  94.102.49.193		# cloud.census.shodan.io
                  185.181.102.18		# turtle.census.shodan.io
                  

                  Andy

                  1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

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                  • L
                    leungda
                    last edited by

                    Could you tell me how to create a blacklist in snort?

                    1 Reply Last reply Reply Quote 0
                    • NogBadTheBadN
                      NogBadTheBad
                      last edited by

                      Create the blacklist file:-

                      0_1536609734495_Untitled.jpeg

                      Apply it to the interface:-

                      0_1536609743860_Untitled 2.jpeg

                      You then should see (spp_reputation) packets blacklisted in the blocked list:-

                      0_1536609872518_Untitled 3.jpeg

                      Andy

                      1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

                      1 Reply Last reply Reply Quote 0
                      • L
                        leungda
                        last edited by

                        Love it. Thanks for your help

                        1 Reply Last reply Reply Quote 0
                        • KOMK
                          KOM
                          last edited by

                          @netblues said in DDoS attacks OpenVPN on Pfsense:

                          Are you using a static tls key?

                          You have been asked this twice now. It's hard to help you when you don't answer questions.

                          1 Reply Last reply Reply Quote 0
                          • johnpozJ
                            johnpoz LAYER 8 Global Moderator
                            last edited by

                            You have ZERO need of snort to stop traffic from hitting your wan IP on your openvpn port - ZERO!!!

                            Im with kom - you going to answer the simple TLS key question??

                            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 2.8, 24.11

                            1 Reply Last reply Reply Quote 0
                            • L
                              leungda
                              last edited by leungda

                              I checked. I didn't use TLS key on OpenVPN setting. Might be you can help me to set this up for extra layer.

                              My OpenVPN set up look like this

                              SSL/TLS + user auth -> DUO -> AD for people to sign in. I am not using local database for user auth

                              Do you sugguest any online guide that I can read of TLS?

                              1 Reply Last reply Reply Quote 0
                              • KOMK
                                KOM
                                last edited by

                                I think you just have to check the Use a TLS key box and then generate new user config that has the TLS key embedded in the .ovpn file, for instance.

                                1 Reply Last reply Reply Quote 0
                                • N
                                  netblues
                                  last edited by

                                  The guide on openvpn hardening has lots of info
                                  https://community.openvpn.net/openvpn/wiki/Hardening
                                  tls key is described in section Use of --tls-auth
                                  As for pfsense, its rather straight forward to implement what it suggests.
                                  It also means that you need to send the tls.key to all your clients somehow.
                                  Now if you are running clients by the thousands, this is definitely an issue on its own.
                                  Imagine this as an initial passphrase. If the client connecting knows it, thserver will deal with him further, spending computing resources to do all the needed security handshakes
                                  Obviously it won;t help if you are experiencing a network level attack, ie ping flood saturating your line.

                                  1 Reply Last reply Reply Quote 0
                                  • L
                                    leungda
                                    last edited by leungda

                                    I got the TLS in place at one site. I will keep my eyes on it for the next few days. Also, set up a blocklist on Snort is also a good idea.

                                    This guide is quite useful too. Thanks
                                    https://community.openvpn.net/openvpn/wiki/Hardening

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