# WHATPORT(2401)

## NAME

port 2401 — CVS pserver — CVS's password-authenticating server — version control from before SSH was assumed.

Protocol: TCP  
IANA: cvspserver

## DESCRIPTION

The CVS manual documents 2401 as the default pserver port, historically wired up through inetd or xinetd running `cvs pserver`. A client sends the repository root, username, and password, and gets read/write access to the repository. The manual is blunt about the security: the password is only trivially scrambled, offering no protection against anyone who can sniff packets, and it recommends a separate CVS password file so people do not expose their real account passwords. Today it turns up on legacy source servers and anonymous read-only mirrors of old projects.

## EXPOSURE

**Do not expose.** The CVS manual itself says the scrambling stops inadvertent compromise and nothing more; authenticated pserver on a public IP hands over credentials. Anonymous read-only mirrors are the only defensible case, and even then prefer ssh transport.

## CHECK

```sh
nc -v TARGET 2401
```

## SEE ALSO

- docs — [CVS Manual — Password authentication server (port 2401, inetd/xinetd setup)](https://www.gnu.org/software/trans-coord/manual/cvs/html_node/Password-authentication-server.html) (gnu.org)
- iana — [IANA Service Name and Transport Protocol Port Number Registry — 2401 (cvspserver)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=2401) (iana.org)

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