How severe is CVE-2021-34416?

CVE-2021-34416 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-34416 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-34416?

CVE-2021-34416 primarily affects Zoom Meeting Connector. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-34416?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-34416 published?

CVE-2021-34416 was published on 2021-09-27 and last updated on 2026-06-17.

CVE-2021-34416

CVE-2021-34416 is a critical-severity vulnerability in Zoom Meeting Connector with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (73rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Zoom Meeting Connector
Published: 2021-09-27
Last modified: 2026-06-17

Description

The network address administrative settings web portal for the Zoom on-premise Meeting Connector before version 4.6.360.20210325, Zoom on-premise Meeting Connector MMR before version 4.6.360.20210325, Zoom on-premise Recording Connector before version 3.8.44.20210326, Zoom on-premise Virtual Room Connector before version 4.4.6752.20210326, and Zoom on-premise Virtual Room Connector Load Balancer before version 2.5.5495.20210326 fails to validate input sent in requests to update the network configuration, which could lead to remote command injection on the on-premise image by the web portal administrators.

Frequently asked questions

What is CVE-2021-34416?: The network address administrative settings web portal for the Zoom on-premise Meeting Connector before version 4.6.360.20210325, Zoom on-premise Meeting Connector MMR before version 4.6.360.20210325, Zoom on-premise Recording Connector before version 3.8.44.20210326, Zoom on-premise Virtual Room Connector before version 4.4.6752.20210326, and Zoom on-premise Virtual Room Connector Load Balancer before version 2.5.5495.20210326 fails to validate input sent in requests to update the network configuration, which could lead to remote command injection on the on-premise image by the web portal administrators.
How severe is CVE-2021-34416?: CVE-2021-34416 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-34416 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34416?: CVE-2021-34416 primarily affects Zoom Meeting Connector. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-34416?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-34416 published?: CVE-2021-34416 was published on 2021-09-27 and last updated on 2026-06-17.

References

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

Affected products (4)

cpe:2.3:a:zoom:meeting_connector:*:*:*:*:*:*:*:*
cpe:2.3:a:zoom:recording_connector:*:*:*:*:*:*:*:*
cpe:2.3:a:zoom:virtual_room_connector:*:*:*:*:*:*:*:*
cpe:2.3:a:zoom:virtual_room_connector_load_balancer:*:*:*:*:*:*:*:*

More vulnerabilities in Zoom Meeting Connector

CVE-2022-28750 — High (CVSS 7.5): Zoom On-Premise Meeting Connector Zone Controller (ZC) before version 4.8.20220419.112 fails to properly parse STUN…
CVE-2021-34415 — High (CVSS 7.5): The Zone Controller service in the Zoom On-Premise Meeting Connector Controller before version 4.6.358.20210205 does…
CVE-2021-34414 — High (CVSS 7.2): The network proxy page on the web portal for the Zoom on-premise Meeting Connector Controller before version…
CVE-2022-28754 — High (CVSS 7.1): Zoom On-Premise Meeting Connector MMR before version 4.8.129.20220714 contains an improper access control…
CVE-2022-28753 — High (CVSS 7.1): Zoom On-Premise Meeting Connector MMR before version 4.8.129.20220714 contains an improper access control…

All CVEs affecting Zoom Meeting Connector →

Other CWE-20 (Improper Input Validation) vulnerabilities

CVE-2026-48316 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48281 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48277 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48055 — Critical (CVSS 10.0): Streambert is a cross-platform Electron Desktop App to stream and download any video media. In versions 2.4.0 and…
CVE-2026-34910 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS…
CVE-2026-33587 — Critical (CVSS 10.0): Lack of user input sanitisation in Open Notebook v1.8.3 allows the application user to execute Python code (and…

Browse all CWE-20 (Improper Input Validation) vulnerabilities →