{
  "port": 3351,
  "protocol": "tcp",
  "service": "Btrieve / Actian Zen",
  "oneLiner": "The Btrieve MicroKernel database engine port, still carrying Actian Zen and Pervasive PSQL traffic.",
  "whatItIs": "IANA registers 3351 as `btrieve`, and it remains the listening port of the MicroKernel Engine in Pervasive PSQL and its successor Actian Zen — the modern descendants of Btrieve. Clients reach databases through it directly, including URIs of the form `btrv://servername:port/database`, and Actian's documentation recommends not changing the assignment. It turns up wherever vertical-market Windows applications ship an embedded Zen database: point-of-sale, dental and veterinary practice software, small ERP systems. An open 3351 means a business application's data files are reachable over the network.",
  "exposure": {
    "verdict": "never",
    "note": "It is a database engine port with the application's records behind it and no transport encryption by default; keep it on the LAN and reach it over a VPN."
  },
  "checkCommand": "nc -vz TARGET 3351",
  "links": [
    {
      "title": "Actian Zen — Setting Up Network Communications for Clients",
      "url": "https://docs.actian.com/zen/v16/getstart/clientconf.htm",
      "kind": "official-docs"
    },
    {
      "title": "IANA Service Name and Transport Protocol Port Number Registry",
      "url": "https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml",
      "kind": "iana"
    }
  ]
}