What is CVE-2021-43555?

CVE-2021-43555 is a high-severity vulnerability in Myscada Mydesigner, classified under Relative Path Traversal. CVSS score: 7.3/10. Published 2021-11-19.

How severe is CVE-2021-43555?

High severity. CVSS v3 base score is 7.3 out of 10.

Path Traversal in Myscada Mydesigner

CVE-2021-43555

mySCADA myDESIGNER Versions 8.20.0 and prior fails to properly validate contents of an imported project file, which may make the product vulnerable to a path traversal payload. This vulnerability may allow an attacker to plant files on the file system in arbitrary locations or overwrite existing files, resulting in remote code execution.

Published 2021-11-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:H.

EPSS exploit prediction

EPSS: 0.382 (98.5th percentile), scored 2026-09-28.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 99th percentile — 98.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.380 · newest: 0.382 · change: +0.003

Affected products

Myscada Mydesigner — versions All

Weakness classification (CWE)

References

us-cert.cisa.gov/ics/advisories/icsa-21-313-04 (US Government Resource, Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-43555?: CVE-2021-43555 is a high-severity vulnerability in Myscada Mydesigner, classified under Relative Path Traversal. CVSS score: 7.3/10. Published 2021-11-19.
How severe is CVE-2021-43555?: High severity. CVSS v3 base score is 7.3 out of 10.