When connecting to the Solax Cloud MQTT server the username is the "registration number", which is the 10 character string printed on the SolaX Power Pocket device / the QR code on the device. The password is derived from the "registration number" using a proprietary XOR/transposition algorithm. Attackers with the knowledge of the registration numbers can connect to the MQTT server and impersonate the dongle / inverters.

The firmware update functionality does not verify the authenticity of the supplied firmware update files. This allows attackers to flash malicious firmware update files on the device. Initial analysis of the firmware update functionality does not show any cryptographic checks (e.g. digital signature checks) on the supplied firmware update files. Furthermore, ESP32 security features such as secure boot are not used.

The affected devices do not validate the server certificate when connecting to the SolaX Cloud MQTTS server hosted in the Alibaba Cloud (mqtt001.solaxcloud.com, TCP 8883). This allows attackers in a man-in-the-middle position to act as the legitimate MQTT server and issue arbitrary commands to devices.