What is CVE-2021-21778?

CVE-2021-21778 is a high-severity vulnerability in Mz-Automation Lib60870, classified under Reachable Assertion. CVSS score: 7.5/10. Published 2021-08-25.

How severe is CVE-2021-21778?

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

Vulnerability in Mz-Automation Lib60870

CVE-2021-21778

A denial of service vulnerability exists in the ASDU message processing functionality of MZ Automation GmbH lib60870.NET 2.2.0. A specially crafted network request can lead to loss of communications. An attacker can send an unauthenticated message to trigger this vulnerability.

Published 2021-08-25 · 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:N/A:H.

EPSS exploit prediction

EPSS: 0.013 (69.5th percentile), scored 2026-10-25.

Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 69.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

Mz-Automation Lib60870 — versions 2.2.0
Mz Automation" — versions MZ Automation GmbH lib60870.NET 2.2.0

Weakness classification (CWE)

CWE-617 — Reachable Assertion

References

talosintelligence.com/vulnerability_reports/TALOS-2021-1236 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-21778?: CVE-2021-21778 is a high-severity vulnerability in Mz-Automation Lib60870, classified under Reachable Assertion. CVSS score: 7.5/10. Published 2021-08-25.
How severe is CVE-2021-21778?: High severity. CVSS v3 base score is 7.5 out of 10.