SunGrow WiNet-SV200.001.00.P027 and earlier versions is vulnerable to heap-based buffer overflow due to bounds checks of the MQTT message content.

SunGrow WiNet-SV200.001.00.P027 and earlier versions contains a hardcoded password that can be used to decrypt all firmware updates.

SunGrow WiNet-SV200.001.00.P027 and earlier versions contains hardcoded MQTT credentials that allow an attacker to send arbitrary commands to an arbitrary inverter. It is also possible to impersonate the broker, because TLS is not used to identify the real MQTT broker. This means that MQTT communications are vulnerable to MitM attacks at the TCP/IP level.

In SunGrow WiNet-SV200.001.00.P027 and earlier versions, when copying the timestamp read from an MQTT message, the underlying code does not check the bounds of the buffer that is used to store the message. This may lead to a stack-based buffer overflow.

SunGrow WiNet-SV200.001.00.P027 and earlier versions is vulnerable to stack-based buffer overflow when parsing MQTT messages, due to missing MQTT topic bounds checks.

In SunGrow WiNet-SV200.001.00.P027 and earlier versions, when decrypting MQTT messages, the code that parses specific TLV fields does not have sufficient bounds checks. This may result in a stack-based buffer overflow.

SunGrow WiNet-S V200.001.00.P025 and earlier versions is missing integrity checks for firmware upgrades. Sending a specific MQTT message allows an update to an inverter or a WiNet connectivity dongle with a bogus firmware file that is located on attacker-controlled server.