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    PCI Compliance Port 53

    Scheduled Pinned Locked Moved Firewalling
    3 Posts 3 Posters 5.1k Views
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    • K
      kcnz
      last edited by

      I had a pci scan done through hackerguardian.com and it did not pass pci compliance due to:

      UDP packets with source port of 53 bypass firewall rules

      Further Explanation:

      "Urgent"
      Synopsis :
      Firewall rulesets can be bypassed.
      Description :
      It is possible to bypass the rules of the remote firewall by sending UDP packets with a source port equal to 53.
      An attacker may use this flaw to inject UDP packets to the remote hosts, in spite of the presence of a firewall.

      and a link

      http://archives.neohapsis.com/archives/fulldisclosure/2003-q2/0352.html

      I have no open ports other then openvpn which is running on pfsense.

      How do I eliminate this? I tried blocking the port specifically and it still failed..

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      • jimpJ
        jimp Rebel Alliance Developer Netgate
        last edited by

        I'm not sure why that came back, but it's really a false positive. If you read the notice, it's for "UDP bypassing in Kerio Firewall" - and seeing as this is not Kerio Firewall, it's likely irrelevant. Such a rule does not exist on pfSense anyhow, not by default.

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        • S
          sdamron
          last edited by

          You do not fail PCI compliance for having an open port on your firewall.  Port 53 is DNS, and if you run your own DNS servers, you must have this port open inbound.  You need a real PCI assessment, not some free automated scan.

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