CVE-2021-34418

Name: CVE-2021-34418
Creator: NVD / NIST
Published: 2021-11-11T23:15:09.467+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 0.61%

Last modified Jun 17, 2026

CVE-2021-34418 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. The login routine of the web console in the Zoom On-Premise Meeting Connector before version 4.6.239.20200613, Zoom On-Premise Meeting Connector MMR before version 4.6.239.20200613, Zoom On-Premise Recording Connector before version 3.8.42.20200905, Zoom On-Premise Virtual Room Connector before version 4.4.6344.20200612, and Zoom On-Premise Virtual Room Connector Load Balancer before version 2.5.5492.20200616 fails to validate that a NULL byte was sent while authenticating. This could lead to a crash of the login service.. EPSS estimates a 0.61% chance of exploitation in the next 30 days.

Description

The login routine of the web console in the Zoom On-Premise Meeting Connector before version 4.6.239.20200613, Zoom On-Premise Meeting Connector MMR before version 4.6.239.20200613, Zoom On-Premise Recording Connector before version 3.8.42.20200905, Zoom On-Premise Virtual Room Connector before version 4.4.6344.20200612, and Zoom On-Premise Virtual Room Connector Load Balancer before version 2.5.5492.20200616 fails to validate that a NULL byte was sent while authenticating. This could lead to a crash of the login service.

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

0.61%

44.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-476

Affected Software

Vendor	Product	Versions
Zoom	Zoom On-Premise Meeting Connector Controller	< 4.6.239.20200613
Zoom	Zoom On-Premise Meeting Connector Mmr	< 4.6.239.20200613
Zoom	Zoom On-Premise Recording Connector	< 3.8.42.20200905
Zoom	Zoom On-Premise Virtual Room Connector	< 4.4.6344.20200612
Zoom	Zoom On-Premise Virtual Room Connector Load Balancer	< 2.5.5492.20200616

References

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

Timeline

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

Frequently Asked Questions

What is CVE-2021-34418?

How severe is CVE-2021-34418?

CVE-2021-34418 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.61% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34418?

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-2021-34418?

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

Scan your code now

Source: NVD / NIST