My pull request to add a new console prompt was accepted today. The new prompt suppresses the echoing of the typed characters, or optionally echoes *s on character entry, making it suitable for prompting for passwords.
The changes were merged into the develop branch and should be in Zend Framework 2 in version 2.4. In the meantime you can install the console password prompt as a zend framework module. The package is Richardjh\zf2-password on Packagist and is installable using composer.