CVE-2021-34413
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAll 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA Time-of-check Time-of-use (TOC/TOU) race condition exists in the Zoom Plugin for Microsoft Outlook for MacOS installation process. During installation, there is a window where a standard local user can write a malicious application to the plugin directory before the privileged installation process executes it, achieving code execution in an elevated context.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 5.3.52553.0918CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Locate the Zoom Plugin for Microsoft Outlook on macOSSearch for the plugin application in /Applications folder or check ~/Library/Application Support/Zoom/ and /Library/Application Support/Zoom/ for plugin componentsAffected if The Zoom Plugin for Microsoft Outlook is present on the system
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Identify the installed version of the pluginRight-click the Zoom Plugin For Microsoft Outlook.app in Applications, select Get Info, and note the Version number shown under the General information sectionAffected if The displayed version number is lower than 5.3.52553.0918
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Alternative version check via plugin package contentsIf available, navigate to the plugin app bundle Contents/Info.plist and check the CFBundleShortVersionString or CFBundleVersion valueAffected if The version string extracted from the bundle is lower than 5.3.52553.0918
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Confirm the installation directory permissionsInspect the permissions of the directory where the plugin is installed (typically in Application Support folders) by running ls -la on the pathAffected if Standard user accounts have write access to the plugin installation directory
A user is affected if the Zoom Plugin for Microsoft Outlook is installed on macOS and its version is lower than 5.3.52553.0918, making the TOC/TOU race condition exploitable during installation or updates.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped5.3.52553.0918
Update the Zoom Plugin for Microsoft Outlook on macOS to version 5.3.52553.0918 or later. Alternatively, remove or disable the plugin until patching is feasible.
Zoom Plugin for Microsoft Outlook for macOS version 5.3.52553.0918 or later
- Navigate to the official Zoom download page (explore.zoom.us) or open the Zoom desktop client
- Locate the Zoom Plugin for Microsoft Outlook for macOS download section
- Download version 5.3.52553.0918 or later
- Open the downloaded installer package
- Follow the on-screen installation prompts to complete the upgrade
- Restart Microsoft Outlook to ensure the updated plugin loads properly
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-34413 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-34413 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data