{
  "port": 18101,
  "protocol": "tcp",
  "service": "Unassigned",
  "oneLiner": "Unregistered; the only true statement about a listener here is that something picked the number.",
  "whatItIs": "IANA does not assign 18101 — the closest registration in the range is 18104 (radpdf, RAD PDF Service), which is a different port. Nmap has no service name for 18101 and scans it by default only because its measured open-port frequency puts it in the top 1000. No widely deployed software documents it as a default.",
  "exposure": {
    "verdict": "careful",
    "note": "No known protocol means no known authentication or encryption story. Fingerprint before you decide, and default to closed at the perimeter."
  },
  "checkCommand": "nmap -Pn -sV -p 18101 TARGET",
  "links": [
    {
      "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"
    },
    {
      "title": "Nmap services frequency database",
      "url": "https://github.com/nmap/nmap/blob/master/nmap-services",
      "kind": "github"
    }
  ]
}