CHARGEN — an endless stream of printable characters, and a classic DDoS amplification source.
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.
Do not expose
A documented high-ratio UDP amplification vector in CISA's alert; an internet-reachable CHARGEN server is a weapon pointed at third parties.
$ nc -v TARGET 19 | head -c 200Seen this on your network? Beige Box scans your Wi-Fi and shows every open port on every device — and its Ports tool links straight back here.
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