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    pfSense weak DH vuln found with Kali

    Scheduled Pinned Locked Moved General pfSense Questions
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    • 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

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      • 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/

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          • 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

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                • 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/

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                    • 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/

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                          • P Offline
                            pooperman
                            last edited by

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

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