Internet-Security.com TCP port 9051 details

TCP port 9051 is used by Tor’s ControlPort, which speaks the Tor Control Protocol.
The tor daemon (as packaged on Linux/BSD and in the Tor Expert Bundle for Windows/macOS) commonly listens on 127.0.0.1:9051 for administrative control.
Tools such as Nyx (formerly arm), the Python Stem library, and the legacy Vidalia GUI connect to 9051 to monitor Tor and issue commands (e.g., GETINFO, SIGNAL NEWNYM).
Privacy-focused systems like Tails and some Whonix setups run Tor with a local ControlPort on 9051 so system components can manage circuits and onion services.
Some Android deployments (e.g., Orbot) can expose a local Tor control port on 9051 for their UI and compatible apps.
If misconfigured and exposed beyond localhost or without authentication, 9051 can be abused to send Tor control commands; best practice is to bind it to localhost and require CookieAuth or a hashed control password.

TCP 9051