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    pfSense weak DH vuln found with Kali

    Scheduled Pinned Locked Moved General pfSense Questions
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    • NogBadTheBadN Offline
      NogBadTheBad @johnpoz
      last edited by NogBadTheBad

      @johnpoz @BBcan177

      Ah it's DNSBL.

      Hmmm disable DNSBL and its a pass.

      If I look at the cert and the key size is 2048.

      Screenshot 2019-03-25 at 19.14.03.png

      Andy

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

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

        Key size is not the same has DH size... Sorry but out of the box the DH is 4096..

        I just fired up a 2.4.4p1 clean VM... nothing more than clicking ok in the wizard and this is what the out of the box gui offers

         Testing 370 ciphers via OpenSSL plus sockets against the server, ordered by encryption strength 
        
        Hexcode  Cipher Suite Name (OpenSSL)       KeyExch.   Encryption  Bits     Cipher Suite Name (IANA/RFC)
        -----------------------------------------------------------------------------------------------------------------------------
         xc030   ECDHE-RSA-AES256-GCM-SHA384       ECDH 256   AESGCM      256      TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384              
         xc028   ECDHE-RSA-AES256-SHA384           ECDH 256   AES         256      TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384              
         xc014   ECDHE-RSA-AES256-SHA              ECDH 256   AES         256      TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA                 
         x9f     DHE-RSA-AES256-GCM-SHA384         DH 4096    AESGCM      256      TLS_DHE_RSA_WITH_AES_256_GCM_SHA384                
         x6b     DHE-RSA-AES256-SHA256             DH 4096    AES         256      TLS_DHE_RSA_WITH_AES_256_CBC_SHA256                
         x39     DHE-RSA-AES256-SHA                DH 4096    AES         256      TLS_DHE_RSA_WITH_AES_256_CBC_SHA                   
         xc02f   ECDHE-RSA-AES128-GCM-SHA256       ECDH 256   AESGCM      128      TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256              
         x9e     DHE-RSA-AES128-GCM-SHA256         DH 4096    AESGCM      128      TLS_DHE_RSA_WITH_AES_128_GCM_SHA256                
        
        
         Running client simulations (HTTP) via sockets 
        
         Android 4.2.2                No connection
         Android 4.4.2                TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Android 5.0.0                TLSv1.2 ECDHE-RSA-AES128-GCM-SHA256, 256 bit ECDH (P-256)
         Android 6.0                  TLSv1.2 ECDHE-RSA-AES128-GCM-SHA256, 256 bit ECDH (P-256)
         Android 7.0                  TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Chrome 65 Win 7              TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Chrome 70 Win 10             TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Firefox 59 Win 7             TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Firefox 62 Win 7             TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         IE 6 XP                      No connection
         IE 7 Vista                   No connection
         IE 8 Win 7                   No connection
         IE 8 XP                      No connection
         IE 11 Win 7                  TLSv1.2 DHE-RSA-AES256-GCM-SHA384, 4096 bit DH  (ffdhe4096)
         IE 11 Win 8.1                TLSv1.2 DHE-RSA-AES256-GCM-SHA384, 4096 bit DH  (ffdhe4096)
         IE 11 Win Phone 8.1          TLSv1.2 ECDHE-RSA-AES256-SHA, 256 bit ECDH (P-256)
         IE 11 Win 10                 TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Edge 13 Win 10               TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Edge 13 Win Phone 10         TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Edge 15 Win 10               TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Opera 17 Win 7               TLSv1.2 ECDHE-RSA-AES256-SHA, 256 bit ECDH (P-256)
         Safari 9 iOS 9               TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Safari 9 OS X 10.11          TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Safari 10 OS X 10.12         TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Apple ATS 9 iOS 9            TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Tor 17.0.9 Win 7             No connection
         Java 6u45                    No connection
         Java 7u25                    No connection
         Java 8u161                   TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         Java 9.0.4                   TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         OpenSSL 1.0.1l               TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
         OpenSSL 1.0.2e               TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 256 bit ECDH (P-256)
        
        

        So not sure what he is testing, but it sure isn't pfsense gui..

        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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        • 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

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            • 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?

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                • 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)?

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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

                      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/

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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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