CVE-2021-33907

Name: CVE-2021-33907
Creator: NVD / NIST
Published: 2021-09-27T14:15:08.027+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 3.02%

Last modified Jun 17, 2026

CVE-2021-33907 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. The Zoom Client for Meetings for Windows in all versions before 5.3.0 fails to properly validate the certificate information used to sign .msi files when performing an update of the client. This could lead to remote code execution in an elevated privileged context.. EPSS estimates a 3.02% chance of exploitation in the next 30 days.

Description

The Zoom Client for Meetings for Windows in all versions before 5.3.0 fails to properly validate the certificate information used to sign .msi files when performing an update of the client. This could lead to remote code execution in an elevated privileged context.

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

3.02%

85.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-295

Affected Software

Vendor	Product	Versions
Zoom	Meetings	< 5.3.0

References

https://explore.zoom.us/en/trust/security/security-bulletin/Vendor Advisory
https://explore.zoom.us/en/trust/security/security-bulletin/Vendor Advisory

Timeline

Published: Sep 27, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-33907?

How severe is CVE-2021-33907?

CVE-2021-33907 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 3.02% probability of exploitation in the next 30 days.

How do I fix CVE-2021-33907?

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-2021-33907?

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

Scan your code now

Source: NVD / NIST