FTP

The File Transfert Protocole (FTP) is a network protocol used for the transfer of files between a client and a server. This service is commonly exposed on port 21.

Anonymous login

Some FTP server allow anonymous authentication, that means a user can login with the anonymous username and no passwords.

You can check if the server supports this features with multiple tools:

  • with a nmap script: nmap --script=ftp-anon -p{PORT} {HOST}
  • with a browser: type the following URL ftp://{HOST}:{PORT}
  • manually with netcat or telnet: telnet {HOST} {PORT}

SFTP port forwarding

SFTP runs as a subsystem of SSH. As with SSH, it's possible to test for port forwarding if there is a bad configuration on the SSH server.