CVE-2021-34418
Pre-auth Null pointer crash in on-premise web console
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Pre-auth Null pointer crash in on-premise web console
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.
- Record
CVE-2021-34418- CVSS 3.1
- 4.0 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
EUVDEUVD-2021-21076
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.
- Record
EUVD-2021-21076- CVSS 3.1
- 4.0 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-9m9w-fffc-45mm No score
The login routine of the web console in the Zoom On-Premise Meeting Connector before version 4.6...
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.
- Record
GHSA-9m9w-fffc-45mm- Weakness
- CWE-476
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2021-34418- CVSS 3.1
- 4.0 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-476
- Updated
- 2026-11-02
Affected products
- zoom on-premise meeting connector mmr
- zoom on-premise recording connector
- zoom on-premise virtual room connector
- zoom on-premise virtual room connector load balancer
- zoom on-premise meeting connector controller
- zoom video communications inc on-premise meeting connector
- zoom video communications inc on-premise meeting connector mmr
- zoom video communications inc on-premise recording connector
- zoom video communications inc on-premise virtual room connector
- zoom video communications inc on-premise virtual room connector load balancer
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-34418 is a medium vulnerability (CVSS 4.0) in Zoom On-premise Meeting Connector Mmr, published November 11, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.63%, the 50th percentile. No source names a fixed version.