Vulnerability · Published Jun 11, 2025 · Assigned by DIVD

CVE-2025-29756MQTT implementation in Sungrow iSolarCloud allowed users to subscribe to all data of all connected inverters

High 8.3

In plain English

A high-severity missing authorization in iSolarCloud from SunGrow. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities).

Severity (CVSS 4.0)8.3High

Exploit odds (30 days)0.3%top 83.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

SunGrow's back end users system iSolarCloud https://isolarcloud.com uses an MQTT service to transport data from the user's connected devices to the user's web browser. The MQTT server however did not have sufficient restrictions in place to limit the topics that a user could subscribe to. While the data that is transmitted through the MQTT server is encrypted and the credentials for the MQTT server are obtained though an API call, the credentials could be used to subscribe to any topic and the encryption key can be used to decrypt all messages received. An attack with an account on iSolarCloud.com could extract MQTT credentials and the decryption key from the browser and then use an external program to subscribe to the topic '#' and thus recieve all messages from all connected devices.

Affected products (as reported)

Vendor	Product	Versions
SunGrow	iSolarCloud	0 – before 7 June 2025

Weakness: CWE-862 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/AU:Y

References

https://csirt.divd.nl/CVE-2025-29756 third-party-advisory, technical-description
https://csirt.divd.nl/DIVD-2025-00009 third-party-advisory
https://isolarcloud.com product