What is CVE-2017-9855?

CVE-2017-9855 is a critical-severity vulnerability in Sma Sunny Boy 1.5, classified under Incorrect Authorization. CVSS score: 9.8/10. Published 2017-08-05.

How severe is CVE-2017-9855?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in Sma Sunny Boy 1.5

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

Vulnerability class: Broken Access Control

Published 2017-08-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.016 (74.6th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 74.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

Frequently asked questions

What is CVE-2017-9855?: CVE-2017-9855 is a critical-severity vulnerability in Sma Sunny Boy 1.5, classified under Incorrect Authorization. CVSS score: 9.8/10. Published 2017-08-05.
How severe is CVE-2017-9855?: Critical severity. CVSS v3 base score is 9.8 out of 10.