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    pfSense weak DH vuln found with Kali

    Scheduled Pinned Locked Moved General pfSense Questions
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    • P Offline
      pooperman
      last edited by pooperman

      DNSBL is also running on my pfsense

      maybe kali checked the DNSBL cert?
      @johnpoz thanks for rechecking!

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

        @pooperman is running pfblocker as well.

        https://forum.netgate.com/topic/141220/pfblockerng-very-slow-at-dns

        Andy

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

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

          @pooperman said in pfSense weak DH vuln found with Kali:

          DNSBL is also running on my pfsense

          maybe kali checked the DNSBL cert?
          @johnpoz thanks for rechecking!

          Yup stop DNSBL and you'll get a pass.

          Andy

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

          1 Reply Last reply Reply Quote 1
          • P Offline
            pooperman
            last edited by

            just to get it right, DNSBL shall just redirect unwanted "data".
            In order to keep integrity, it is using a cert and this cert is having insuffizient DH strength?

            If so, according to my understanding there is actually no problem. In case someone breaks encryption it will just get all the rubbish that I do not want, correct?

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

              @pooperman said in pfSense weak DH vuln found with Kali:

              DNSBL

              ask @BBcan177 maybe he can shed some light on what his package is doing... If its serving up something on https, then it should be using current best practices to do so..

              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

              P 1 Reply Last reply Reply Quote 1
              • P Offline
                pooperman @johnpoz
                last edited by

                @johnpoz said in pfSense weak DH vuln found with Kali:

                @pooperman said in pfSense weak DH vuln found with Kali:

                DNSBL

                ask @BBcan177 maybe he can shed some light on what his package is doing... If its serving up something on https, then it should be using current best practices to do so..

                thanks for support!

                will an @ and the name triggers something at the users interface in this forum ie. get an altert?
                Or shall i contact him directly?

                may I ask how and where you tested the DH key size (6th post)?

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

                  The @ should send him notification of this post.

                  The script I use to test ssl stuff is here
                  https://github.com/drwetter/testssl.sh

                  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 1
                  • NogBadTheBadN Offline
                    NogBadTheBad
                    last edited by

                    He not been online for 11 days, I've made a post on reddit linking here.

                    Andy

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

                    BBcan177B 1 Reply Last reply Reply Quote 1
                    • BBcan177B Offline
                      BBcan177 Moderator @NogBadTheBad
                      last edited by

                      @NogBadTheBad

                      The function that generates the cert is here:
                      https://github.com/pfsense/FreeBSD-ports/blob/devel/net/pfSense-pkg-pfBlockerNG-devel/files/usr/local/pkg/pfblockerng/pfblockerng.inc#L1024-L1049

                      I don't think its necessary for what the DNSBL server is serving, but you can change the settings in the code, delete the cert and then Force Update for the cert to be re-created with the new settings. If you test it successfully, let me know and I will change the code in the next release.

                      /var/unbound/dnsbl_cert.pem
                      

                      "Experience is something you don't get until just after you need it."

                      Website: http://pfBlockerNG.com
                      Twitter: @BBcan177  #pfBlockerNG
                      Reddit: https://www.reddit.com/r/pfBlockerNG/new/

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

                        Lets be clear is not the cert that the problem
                        https://docs.netgate.com/pfsense/en/latest/certificates/dh-parameters.html

                        What is pfblocker using that would be different than what the web gui is using?

                        We are not sure what they are actually hitting when they are testing.. All I can tell you is not the pfsense web gui.

                        So DNSBL listens on port what for SSL, you set this? 8443? How exactly does it serve this up where would it get its DH-parameters from? See the link above.

                        [2.4.4-RELEASE][admin@sg4860.local.lan]/etc: ls -la dh*
                        -rw-r--r--  1 root  wheel   245 Nov 17  2017 dh-parameters.1024
                        -rw-r--r--  1 root  wheel   424 Nov 17  2017 dh-parameters.2048
                        -rw-r--r--  1 root  wheel   595 Oct  4 08:37 dh-parameters.3072
                        -rw-r--r--  1 root  wheel   769 Nov 17  2017 dh-parameters.4096
                        -rw-r--r--  1 root  wheel  1115 Oct  4 08:37 dh-parameters.6144
                        -rw-r--r--  1 root  wheel  1464 Oct  4 08:37 dh-parameters.8192
                        

                        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

                        BBcan177B 1 Reply Last reply Reply Quote 0
                        • BBcan177B Offline
                          BBcan177 Moderator @johnpoz
                          last edited by

                          @johnpoz

                          It uses lighttpd not nginx that is used by the pfSense gui:
                          https://redmine.lighttpd.net/projects/lighttpd/wiki/Docs_SSL

                          Would have to add the DH params to the dnsbl lighttpd conf file:
                          var/unbound/pfb_dnsbl_lighty.conf

                          That file is auto created so changes will be overwritten. Don't have time to look at it atm.

                          "Experience is something you don't get until just after you need it."

                          Website: http://pfBlockerNG.com
                          Twitter: @BBcan177  #pfBlockerNG
                          Reddit: https://www.reddit.com/r/pfBlockerNG/new/

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                          • johnpozJ Offline
                            johnpoz LAYER 8 Global Moderator
                            last edited by johnpoz

                            Yeah my guess but can not seem to find it in the conf is this
                            ssl.dh-file="{path to dhparams.pem}"

                            So not sure what its using if not called out?

                            To be honest this isn't really that big of deal - other than people doing such scans and thinking the problem is pfsense ;) hehehe

                            I set up pfSense and I was checking for general vulnerabilities.

                            No where did he mention installed "optional" packages xyz, and abc, 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 2.8, 24.11

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

                              Well to be fair he did discover something that should probably be updated, if only to prevent false positives as you say.

                              Steve

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                              • BBcan177B Offline
                                BBcan177 Moderator
                                last edited by BBcan177

                                Edit the file (for pfBlockerNG-devel):

                                /usr/local/pkg/pfblockerng/pfblockerng.inc
                                

                                And add the 6 "+" lines as depicted in this screenshot:
                                lighttpd.JPG

                                        $SERVER["socket"] == "127.0.0.1:8443" {
                                                ssl.engine      = "enable"
                                                ssl.pemfile     = "/var/unbound/dnsbl_cert.pem"
                                                ssl.dh-file       = "/etc/dh-parameters.4096"
                                                ssl.cipher-list  = "EECDH+AESGCM:EDH+AESGCM:AES128+EECDH:AES128+EDH"
                                                ssl.ec-curve    = "secp384r1"
                                        }
                                
                                        $SERVER["socket"] == "10.10.10.2:443" {
                                                ssl.engine      = "enable"
                                                ssl.pemfile     = "/var/unbound/dnsbl_cert.pem"
                                                ssl.dh-file       = "/etc/dh-parameters.4096"
                                                ssl.cipher-list  = "EECDH+AESGCM:EDH+AESGCM:AES128+EECDH:AES128+EDH"
                                                ssl.ec-curve    = "secp384r1"
                                        }
                                

                                Stop the pfb_dnsbl Service
                                Then remove the existing lighttpd config file.

                                rm /var/unbound/pfb_dnsbl_lighty.conf
                                

                                Then Force Update for it to be re-created with the new changes.
                                Please post back after running your vulnerability scans.
                                Thanks!

                                "Experience is something you don't get until just after you need it."

                                Website: http://pfBlockerNG.com
                                Twitter: @BBcan177  #pfBlockerNG
                                Reddit: https://www.reddit.com/r/pfBlockerNG/new/

                                1 Reply Last reply Reply Quote 5
                                • johnpozJ Offline
                                  johnpoz LAYER 8 Global Moderator
                                  last edited by johnpoz

                                  As always @BBcan177 your johnny on the spot!

                                  And also took the time to update the cipher list and curve.. Nice!

                                  @stephenw10 agree its a good find, even if found in a round about way.

                                  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 1
                                  • NogBadTheBadN Offline
                                    NogBadTheBad
                                    last edited by

                                    @BBcan177 said in pfSense weak DH vuln found with Kali:

                                    rm /var/unbound/pfb_dnsbl_lighty.conf

                                    mac-pro:~ andy$ nmap --script ssl-dh-params.nse 172.16.0.1

                                    Starting Nmap 7.40 ( https://nmap.org ) at 2019-03-26 09:27 GMT
                                    Nmap scan report for pfsense (172.16.0.1)
                                    Host is up (0.0018s latency).
                                    Not shown: 995 filtered ports
                                    PORT STATE SERVICE
                                    22/tcp open ssh
                                    53/tcp open domain
                                    443/tcp open https
                                    8081/tcp open blackice-icecap
                                    8443/tcp open https-alt

                                    Nmap done: 1 IP address (1 host up) scanned in 6.40 seconds
                                    mac-pro:~ andy$

                                    Yea that fixed it :)

                                    Andy

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

                                    BBcan177B 1 Reply Last reply Reply Quote 0
                                    • BBcan177B Offline
                                      BBcan177 Moderator @NogBadTheBad
                                      last edited by

                                      @NogBadTheBad said in pfSense weak DH vuln found with Kali:

                                      Yea that fixed it :)

                                      Thanks for testing... Will add it to the next release...

                                      "Experience is something you don't get until just after you need it."

                                      Website: http://pfBlockerNG.com
                                      Twitter: @BBcan177  #pfBlockerNG
                                      Reddit: https://www.reddit.com/r/pfBlockerNG/new/

                                      1 Reply Last reply Reply Quote 3
                                      • P Offline
                                        pooperman
                                        last edited by

                                        many thanks for checking /helping and fixing it, to all.
                                        Really appreciated!

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