# WHATPORT(79)

## NAME

port 79 — Finger — Finger — ask a host who is logged in, or look up a specific user's details, in cleartext.

Protocol: TCP  
IANA registry

## DESCRIPTION

RFC 1288 defines Finger as a one-line query protocol: send a username and CRLF to get that user's real name, home directory, shell, login times and the contents of their .plan file, or send an empty line to list everyone currently logged in. That is user enumeration as a service, and the RFC itself devotes a long security section to the fact. It ran as an inetd built-in on nearly every classic UNIX host and was a vector in the 1988 Morris worm through a buffer overflow in fingerd. GNU Inetutils still ships a client and server, but no mainstream system enables it.

## EXPOSURE

**Do not expose.** It hands out account names, login times and home directories to anyone who asks, unauthenticated and in cleartext — direct reconnaissance material.

## CHECK

```sh
printf '\r\n' | nc -v TARGET 79
```

## SEE ALSO

- spec — [RFC 1288 — The Finger User Information Protocol](https://www.rfc-editor.org/rfc/rfc1288.html) (rfc-editor.org)
- docs — [GNU Inetutils (finger client and fingerd)](https://www.gnu.org/software/inetutils/) (gnu.org)
- iana — [IANA Service Name and Transport Protocol Port Number Registry](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml) (iana.org)

---

HTML: <https://whatport.net/79/> · JSON: <https://whatport.net/79.json> · full dataset: <https://whatport.net/ports.json>