# WHATPORT(1000)

## NAME

port 1000 — cadlock2 (registration) — in practice, a round number — Registered as cadlock2, but open 1000s are almost always something that just wanted a memorable port.

Protocol: TCP  
IANA: cadlock2

## DESCRIPTION

IANA's assignment is cadlock2, an old registration with no description and no published protocol. Whatever is listening on 1000 was placed there on purpose by a local admin or application — proxies, internal application servers and management UIs all like the round number. Note that 1000 is still below 1024, so on a Unix-like host binding it required root, which narrows the field to services started with privilege. nmap's data shows it open more often than its neighbours, and that is squatting rather than cadlock.

## EXPOSURE

**Expose with care.** The port name tells you nothing, so judge the service you find. A privileged process listening on a nonstandard port is worth identifying before you allow it through anything.

## CHECK

```sh
curl -sv -o /dev/null --max-time 5 http://TARGET:1000/
```

## SEE ALSO

- iana — [IANA port registry — 1000](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=1000) (iana.org)
- source — [nmap-services (1000/tcp cadlock)](https://github.com/nmap/nmap/blob/master/nmap-services) (github.com)

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HTML: <https://whatport.net/1000/> · JSON: <https://whatport.net/1000.json> · full dataset: <https://whatport.net/ports.json>