What is CVE-2020-21474?

CVE-2020-21474 is a critical-severity vulnerability in Nucleuscms, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2023-06-20.

How severe is CVE-2020-21474?

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

Arbitrary file upload in Nucleuscms

CVE-2020-21474

File Upload vulnerability in NucleusCMS v.3.71 allows a remote attacker to execute arbitrary code via the /nucleus/plugins/skinfiles/?dir=rsd parameter.

Vulnerability class: Unrestricted File Upload

Published 2023-06-20 · 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: 0.012 (66.2th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 66th percentile — 66.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Nucleuscms — versions 3.71

Weakness classification (CWE)

CWE-434 — Unrestricted Upload of File with Dangerous Type

References

github.com/NucleusCMS/NucleusCMS/issues/95 (Exploit, Issue Tracking)

Frequently asked questions

What is CVE-2020-21474?: CVE-2020-21474 is a critical-severity vulnerability in Nucleuscms, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2023-06-20.
How severe is CVE-2020-21474?: Critical severity. CVSS v3 base score is 9.8 out of 10.