Weak Password Requirements vulnerability in Mitsubishi Electric Corporation photovoltaic system monitor “EcoGuideTAB” PV-DR004J all versions and PV-DR004JA all versions allows an attacker within the Wi-Fi communication range between the units of the product (measurement unit and display unit) to derive the password from the SSID. In addition, if the product is configured to enable the individual air conditioner control function, an attacker who has access to the Wi-Fi communication between the units by exploiting this vulnerability may be able to execute ECHONET Lite commands to perform operations such as turning the air conditioner on or off and changing the set temperature. The individual air conditioner control function is available only in display unit version 02.00.01 or later and measurement unit version 02.03.01 or later. The affected products discontinued in 2015, support ended in 2020.