LiveActive security incident?Get immediate response
CVE Record

CVE-2021-34413: All versions of the Zoom Plugin for Microsoft Outlook for MacOS before 5.3.52553.0918 contain a Time-of-che...

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.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This is a local privilege-risk issue in the Zoom Plugin for Microsoft Outlook on macOS. Versions before 5.3.52553.0918 could let a standard user place a malicious application in the plugin directory during installation, causing it to run with elevated privileges. Treat it as an endpoint hardening and software currency issue, especially on managed Macs.

Executive priority

Address this as a moderate-priority endpoint risk. It requires local opportunity and affected software, but successful abuse could elevate privileges on a Mac. The main business action is to identify vulnerable plugin versions and complete updates or removals.

Technical view

The reported flaw is a time-of-check/time-of-use issue in the macOS Outlook Zoom plugin installation process. The source states that a standard user could write a malicious application to the plugin directory and have it execute in a privileged context. No CVSS score, CWE, or detailed vendor mitigation is provided in the source bundle.

Likely exposure

Exposure is limited to macOS systems with the Zoom Plugin for Microsoft Outlook installed at versions before 5.3.52553.0918. Organizations with managed Mac fleets, Outlook users, and legacy Zoom plugin deployments should prioritize inventory. The source bundle does not identify other Zoom products as affected.

Exploitation context

The CVE describes local privilege escalation during plugin installation, not a remote unauthenticated attack. The source bundle does not report active exploitation, and KEV status is false. Evidence is insufficient to claim public exploitation or weaponized use.

Researcher notes

The available record is concise: affected product, version threshold, TOC/TOU class, and privileged execution impact are stated, but scoring and exploit evidence are absent. Do not broaden scope beyond the macOS Outlook Zoom plugin unless future vendor sources say so.

Mitigation direction

  • Update the Zoom Plugin for Microsoft Outlook for macOS to 5.3.52553.0918 or later.
  • Check Zoom’s security bulletin for current vendor guidance before broad remediation.
  • Remove the plugin from endpoints where it is no longer required.
  • Prioritize managed Macs used by Outlook users for software inventory and update enforcement.

Validation and detection

  • Inventory macOS endpoints for the Zoom Plugin for Microsoft Outlook version.
  • Confirm no installed plugin version is earlier than 5.3.52553.0918.
  • Review endpoint management records for legacy plugin installation activity.
  • Check plugin directories for unexpected applications where exposure is suspected.
Prepared
Confidence
medium
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2021-34413 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/aZoom Plugin for Microsoft Outlook for MacOSAll versions before 5.3.52553.0918Listed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.