What is CVE-2021-34543?

CVE-2021-34543 is a high-severity vulnerability in Bkw Solar-Log 500, classified under Missing Authentication for Critical Function. CVSS score: 7.5/10. Published 2021-12-07.

How severe is CVE-2021-34543?

High severity. CVSS v3 base score is 7.5 out of 10.

Auth bypass in Bkw Solar-Log 500

CVE-2021-34543

The web administration server in Solar-Log 500 before 2.8.2 Build 52 does not require authentication, which allows remote attackers to gain administrative privileges by connecting to the server. As a result, the attacker can modify configuration files and change the system status. Fixed with 3.0.0-60 11.10.2013 for SL 200, 500, 1000 / not existing for SL 250, 300, 1200, 2000, SL 50 Gateway, SL Base.

Vulnerability class: Broken Authentication

Published 2021-12-07 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.030 (87.0th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 87th percentile — 87.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.029 · newest: 0.030 · change: +0.001

Affected products

Bkw Solar-Log 500
Bkw Solar-Log 500 Firmware — versions 2.8.2

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

References

drive.google.com/file/d/1z1TaANlDyX4SOP2vjNzkPQI3nETL9kZM/view (Exploit, Third Party Advisory)
www.solar-log.com/en/support/firmware/ (Product, Release Notes, Vendor Advisory)
www.exploit-db.com/exploits/49986 (Exploit, VDB Entry, Third Party Advisory)

Frequently asked questions

What is CVE-2021-34543?: CVE-2021-34543 is a high-severity vulnerability in Bkw Solar-Log 500, classified under Missing Authentication for Critical Function. CVSS score: 7.5/10. Published 2021-12-07.
How severe is CVE-2021-34543?: High severity. CVSS v3 base score is 7.5 out of 10.