CVE-2020-21359

Name: CVE-2020-21359
Creator: NVD / NIST
Published: 2021-08-11T21:15:07.873+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.73%

Last modified Jun 17, 2026

CVE-2020-21359 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. An arbitrary file upload vulnerability in the Template Upload function of Maccms10 allows attackers bypass the suffix whitelist verification to execute arbitrary code via adding a character to the end of the uploaded file's name.. EPSS estimates a 1.73% chance of exploitation in the next 30 days.

Description

An arbitrary file upload vulnerability in the Template Upload function of Maccms10 allows attackers bypass the suffix whitelist verification to execute arbitrary code via adding a character to the end of the uploaded file's name.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.73%

74.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-434

Affected Software

Vendor	Product	Versions
Maccms	Maccms	10.0

References

https://github.com/magicblack/maccms10/issues/80Exploit, Issue Tracking, Third Party Advisory
https://github.com/magicblack/maccms10/issues/80Exploit, Issue Tracking, Third Party Advisory

Timeline

Published: Aug 11, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-21359?

How severe is CVE-2020-21359?

CVE-2020-21359 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.73% probability of exploitation in the next 30 days.

How do I fix CVE-2020-21359?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-21359?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST