CVE-2017-9855: An issue was discovered in SMA Solar Technology products. A secondary authentication system is available for Installers called the Grid Guard system. ...

Description

An issue was discovered in SMA Solar Technology products. A secondary authentication system is available for Installers called the Grid Guard system. This system uses predictable codes, and a single Grid Guard code can be used on any SMA inverter. Any such code, when combined with the installer account, allows changing very sensitive parameters. NOTE: the vendor reports that Grid Guard is not an authentication feature; it is only a tracing feature. Also, only Sunny Boy TLST-21 and TL-21 and Sunny Tripower TL-10 and TL-30 could potentially be affected

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.58%

72.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-863

Affected Software

Vendor	Product	Versions
Sma	Sunny Boy 3600 Firmware	All versions
Sma	Sunny Boy 5000 Firmware	All versions
Sma	Sunny Tripower Core1 Firmware	All versions
Sma	Sunny Tripower 15000tl Firmware	All versions
Sma	Sunny Tripower 20000tl Firmware	All versions
Sma	Sunny Tripower 25000tl Firmware	All versions
Sma	Sunny Tripower 5000tl Firmware	All versions
Sma	Sunny Tripower 12000tl Firmware	All versions
Sma	Sunny Tripower 60 Firmware	All versions
Sma	Sunny Boy 3000tl Firmware	All versions
Sma	Sunny Boy 3600tl Firmware	All versions
Sma	Sunny Boy 4000tl Firmware	All versions
Sma	Sunny Boy 5000tl Firmware	All versions
Sma	Sunny Boy 1.5 Firmware	All versions
Sma	Sunny Boy 2.5 Firmware	All versions
Sma	Sunny Boy 3.0 Firmware	All versions
Sma	Sunny Boy 3.6 Firmware	All versions
Sma	Sunny Boy 4.0 Firmware	All versions
Sma	Sunny Boy 5.0 Firmware	All versions
Sma	Sunny Central 2200 Firmware	All versions
Sma	Sunny Central 1000cp Xt Firmware	All versions
Sma	Sunny Central 800cp Xt Firmware	All versions
Sma	Sunny Central 850cp Xt Firmware	All versions
Sma	Sunny Central 900cp Xt Firmware	All versions
Sma	Sunny Central 500cp Xt Firmware	All versions
Sma	Sunny Central 630cp Xt Firmware	All versions
Sma	Sunny Central 720cp Xt Firmware	All versions
Sma	Sunny Central 760cp Xt Firmware	All versions
Sma	Sunny Central Storage 500 Firmware	All versions
Sma	Sunny Central Storage 630 Firmware	All versions
Sma	Sunny Central Storage 720 Firmware	All versions
Sma	Sunny Central Storage 760 Firmware	All versions
Sma	Sunny Central Storage 800 Firmware	All versions
Sma	Sunny Central Storage 850 Firmware	All versions
Sma	Sunny Central Storage 900 Firmware	All versions
Sma	Sunny Central Storage 1000 Firmware	All versions
Sma	Sunny Central Storage 2200 Firmware	All versions
Sma	Sunny Central Storage 2500-Ev Firmware	All versions
Sma	Sunny Boy Storage 2.5 Firmware	All versions

References

Timeline

Published: Aug 5, 2017
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2017-9855?

An issue was discovered in SMA Solar Technology products. A secondary authentication system is available for Installers called the Grid Guard system. This system uses predictable codes, and a single Grid Guard code can be used on any SMA inverter. Any such code, when combined with the installer account, allows changing very sensitive parameters. NOTE: the vendor reports that Grid Guard is not an authentication feature; it is only a tracing feature. Also, only Sunny Boy TLST-21 and TL-21 and Sunny Tripower TL-10 and TL-30 could potentially be affected

How severe is CVE-2017-9855?

CVE-2017-9855 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.58% probability of exploitation in the next 30 days.

How do I fix CVE-2017-9855?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.