{
  "port": 19,
  "protocol": "both",
  "service": "CHARGEN (Character Generator)",
  "oneLiner": "CHARGEN — an endless stream of printable characters, and a classic DDoS amplification source.",
  "whatItIs": "RFC 864 defines CHARGEN as a test service: over TCP it sends an unending pattern of ASCII characters until the client disconnects, and over UDP it answers each datagram with a random-length payload of up to 512 characters. It was written to exercise packet generation and printer paths, and shipped as an inetd built-in and a Windows Simple TCP/IP Services component. It is disabled by default on modern systems. Its UDP form is one of the most abused reflectors on the internet because a tiny spoofed request produces a much larger reply aimed at the victim.",
  "exposure": {
    "verdict": "never",
    "note": "A documented high-ratio UDP amplification vector in CISA's alert; an internet-reachable CHARGEN server is a weapon pointed at third parties."
  },
  "checkCommand": "nc -v TARGET 19 | head -c 200",
  "links": [
    {
      "title": "RFC 864 — Character Generator Protocol",
      "url": "https://www.rfc-editor.org/rfc/rfc864.html",
      "kind": "spec"
    },
    {
      "title": "CISA Alert — UDP-Based Amplification Attacks",
      "url": "https://www.cisa.gov/news-events/alerts/2014/01/17/udp-based-amplification-attacks",
      "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"
    }
  ]
}