CVE-2021-34413

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-09-27 · updated 2026-06-17
Weakness: CWE-367

Description

All versions of the Zoom Plugin for Microsoft Outlook for MacOS before 5.3.52553.0918 contain a Time-of-check Time-of-use (TOC/TOU) vulnerability during the plugin installation process. This could allow a standard user to write their own malicious application to the plugin directory, allowing the malicious application to execute in a privileged context.

Affected products

Zoom Plugin for Microsoft Outlook for Mac: before 5.3.52553.0918 — fixed in 5.3.52553.0918

How to fix

Upgrade to a fixed version: Zoom Plugin for Microsoft Outlook for Mac 5.3.52553.0918. Check the vendor advisory for mitigations.

References

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

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