Cosy+ devices running a firmware 21.x below 21.2s10 or a firmware 22.x below 22.1s3 use a unique key to encrypt the configuration parameters. This is fixed in version 21.2s10 and 22.1s3, the key is now unique per device.
An issue was discovered on Fujitsu Wireless Keyboard Set LX390 GK381 devices. Because of the lack of proper encryption of 2.4 GHz communication, and because of password-based authentication, they are vulnerable to replay attacks.