Port 512: Rexec
Port 512 is rexec, a legacy protocol for running a command on a remote host that sends the username and password in clear text. It has been replaced by SSH on port 22 for essentially every modern use case.
TCPRemote accessUnencrypted by defaultIANA assigned
| Port number | 512 |
|---|---|
| Service | Remote Process Execution |
| Protocol | TCP |
| Category | Remote access |
| Default encryption | No |
Security note. Port 512 is not encrypted by default. Restrict it to trusted networks, or use an encrypted alternative where one exists, to avoid exposing credentials and data in transit.
Frequently asked questions
What is port 512 used for?
Port 512 is rexec, a legacy protocol for running a command on a remote host that sends the username and password in clear text. It has been replaced by SSH on port 22 for essentially every modern use case.
Is port 512 TCP or UDP?
Port 512 (Rexec) uses TCP.
Is port 512 secure?
Port 512 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 512 on my firewall?
Only if you specifically need Rexec. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.