-Z VerifyServer - Verify TELNET server certificate (yes/no)

The -Z VerifyServer option defines whether the TELNET server certificate should be verified.

-Z VerifyServer

={YES | NO}

YES

The TELNET server certificate should be verified.
YES is the default.

NO

The TELNET server certificate should not be verified.
This setting makes you vulnerable to “man in the middle” attacks.