Recover from wrong Wi-Fi password on Arduino Yún I'm trying to customize my Arduino Yún to work as an access-point (or hotspot) for providing services to clients directly connected and, alternatively, to work as a client on a wireless network for downloading resources from the Internet.

The access to such a wireless network is gained after the user submits a network SSID and password in the web control panel provided by Yún.

How can I recover from a user submitting a wrong password? At the moment the Yún stays stuck without any connection, and thus is unreachable via SSH to attempt any recover.
The simplest option is to provide a serial console interface which will either give full access to the OS (pipe through Console) or a menu driven interface that sends instructions to the main chip (through Bridge).

The user would then connect to the USB interface and use a terminal program to access the configuration in whatever way you have chosen.  This could either be via options within your installed sketch, or by uploading a special sketch through the USB connection.