CVE-2021-20850

Name: CVE-2021-20850
Creator: NVD / NIST
Published: 2021-11-24T16:15:13.483+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.49%

Last modified Jun 17, 2026

CVE-2021-20850 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. PowerCMS XMLRPC API of PowerCMS 5.19 and earlier, PowerCMS 4.49 and earlier, PowerCMS 3.295 and earlier, and PowerCMS 2 Series (End-of-Life, EOL) allows a remote attacker to execute an arbitrary OS command via unspecified vectors.. EPSS estimates a 1.49% chance of exploitation in the next 30 days.

Description

PowerCMS XMLRPC API of PowerCMS 5.19 and earlier, PowerCMS 4.49 and earlier, PowerCMS 3.295 and earlier, and PowerCMS 2 Series (End-of-Life, EOL) allows a remote attacker to execute an arbitrary OS command via unspecified vectors.

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

1.49%

70.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-78

Affected Software

Vendor	Product	Versions
Alfasado	Powercms	>= 2.0, <= 2.058
Alfasado	Powercms	>= 3.01, <= 3.295
Alfasado	Powercms	>= 4.0, <= 4.49
Alfasado	Powercms	>= 5.0, <= 5.19

References

https://jvn.jp/en/jp/JVN17645965/index.htmlThird Party Advisory
https://www.powercms.jp/news/release-patch-xmlrpc-api-202110.htmlPatch, Vendor Advisory
https://jvn.jp/en/jp/JVN17645965/index.htmlThird Party Advisory
https://www.powercms.jp/news/release-patch-xmlrpc-api-202110.htmlPatch, Vendor Advisory

Timeline

Published: Nov 24, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-20850?

How severe is CVE-2021-20850?

CVE-2021-20850 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.49% probability of exploitation in the next 30 days.

How do I fix CVE-2021-20850?

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-2021-20850?

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

Scan your code now

Source: NVD / NIST