whatportis.com
suggest an edit →

Port 19CHARGEN

The Character Generator Protocol (CHARGEN) is a simple network service designed primarily for testing, debugging, and measurement of network performance. When connected, a server running the CHARGEN protocol continuously generates a stream of arbitrary characters until the client closes the connection. Initially developed for diagnostic purposes, this protocol is rarely used in modern systems but still exists on many legacy devices and installations..

inSecurityNetwork Services
transport
tcp · udp

2 transports registered

in transit
cleartext

payload readable on path

assignment
official

registered with iana

risk
5/10

caution

lookups
9,497

rank 501 of 993 · top 50%

Technical Details

what runs on :19

The Character Generator Protocol (CHARGEN), specified in RFC 864, is a straightforward protocol that generates a continuous stream of characters upon request. It operates over both TCP and UDP on port 19, making it versatile but also extremely simplistic in design. When a client connects via TCP, the CHARGEN server sends a steady sequence of printable ASCII characters until the connection is terminated. Over UDP, it responds to incoming datagrams with a packet of characters.

Originally, CHARGEN was intended for network diagnostics, throughput measurement, and load testing. Developers and network administrators used it to generate traffic to evaluate network performance or validate configurations. Despite its usefulness in early networking environments, it lacks any form of authentication, access control, or encryption.

Today, CHARGEN is largely obsolete and seldom used in production networks. Its simplicity and the continuous data stream it provides have made it a legacy protocol, maintained primarily for backward compatibility or legacy device support. Modern network tools have surpassed CHARGEN's capabilities with more precise and configurable alternatives.

Security Information

exposure of :19

risk score

5/ 10caution

worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.

security averages 3.8 across 216 ports — this one sits 1.2 above.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

CHARGEN poses significant security risks due to its unauthenticated, continuous data stream capabilities:

  • It is notoriously used in amplification attacks for Distributed Denial of Service (DDoS). Attackers send spoofed UDP packets to CHARGEN servers, which respond with much larger packets to the spoofed victim, overwhelming their network.
  • The absence of authentication or rate limiting makes it vulnerable to exploitation by malicious actors aiming to generate excess traffic.
  • Historically, misconfigured devices running CHARGEN have been abused as reflectors or amplifiers in attack campaigns.

Mitigations include:

  • Disabling CHARGEN on all modern systems as it is rarely necessary.
  • Blocking inbound and outbound traffic on port 19 at network perimeters.
  • Employing access controls and intrusion detection systems to identify and prevent misuse.
  • Regularly auditing network services to ensure legacy protocols like CHARGEN are not inadvertently exposed.

Related Ports

all 216 in security →

the 8 most looked-up other ports in security — 216 ports carry that label.

portservicerisk
:8881Atlasz Secure Servercaution
:443HTTPScaution
:8291Winbox MikroTik Admincaution
:3268Microsoft Global Catalog (GC)caution
:135Microsoft EPMAPcaution
:3128Squid Proxy HTTPcaution
:8080HTTP Alternatecaution
:7000Vuze HTTPS Trackercaution

risk mix of the 8 listed

  • caution100%

3 of 8 encrypted