If the connection between the client and FTP server is not encrypted, Wireshark will show the username and password.
- Start a capture in Wireshark
- Connect to an FTP Server. Include your username and password in connection.
- Stop the capture in Wireshark.
- In the Wireshark filter, enter FTP.
- In the list of packets, the unencrypted username and password should be displayed.
On the other hand, if the connection between the client and FTP server is encrypted with a SSL/TLS certficate, Wireshark will not show the username and password.