Input validation

FruityWifi (aka PatatasFritas/PatataWifi) 2.1 allows remote attackers to execute arbitrary commands via shell metacharacters in the io_mode, ap_mode, io_action, io_in_iface, io_in_set, io_in_ip, io_in_mask, io_in_gw, io_out_iface, io_out_set, io_out_mask, io_out_gw, iface, or domain parameter to /www/script/config_iface.php, or the newSSID, hostapd_secure, hostapd_wpa_passphrase, or supplicant_ssid parameter to /www/page_config.php.