# WHATPORT(10243)

## NAME

port 10243 — Windows Media Player Network Sharing (HTTP) — A Windows machine with media streaming enabled — HTTP.sys serving the WMPNSSv4 endpoint.

Protocol: TCP  
IANA registry

## DESCRIPTION

Not registered with IANA, but on Windows it is entirely predictable: the Windows Media Player Network Sharing Service reserves the URL http://+:10243/WMPNSSv4/ with HTTP.sys under the NT SERVICE\WMPNetworkSvc account, so the port opens whenever media streaming or DLNA sharing is turned on — often by a setup wizard rather than a deliberate choice. It is the HTTP half of the UPnP AV media server, advertised over SSDP on UDP 1900. Nmap sees it open on about 0.07% of scanned hosts, essentially all Windows.

## EXPOSURE

**Do not expose.** A LAN media-sharing surface with no business on a public IP: it exposes the library to anyone who can reach it and puts HTTP.sys, historically a source of remote vulnerabilities, on the wire. Turn media streaming off if you are not using it.

## CHECK

```sh
curl -sSI http://TARGET:10243/WMPNSSv4/
```

## SEE ALSO

- iana — [IANA port registry — 10243 (no assignment)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=10243) (iana.org)
- source — [nmap-services — Nmap's port frequency database](https://github.com/nmap/nmap/blob/master/nmap-services) (github.com)

---

HTML: <https://whatport.net/10243/> · JSON: <https://whatport.net/10243.json> · full dataset: <https://whatport.net/ports.json>