CVE-2021-34409

Privilege escalation via user-writable installation scripts

Published Sep 27, 2021 · Updated Sep 16, 2024

Local privilege escalation in affected Zoom macOS installers allows local users to execute commands with elevated privileges. The packages copy pre-installation and post-installation shell scripts into a user-writable directory, letting a local user replace code later run by the installer. Exploitation requires local access and installation of an affected package; successful commands run in the installer's higher-privileged context.

CVSS severity7.8
High
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Local privilege escalation in affected Zoom macOS installers allows local users to execute commands with elevated privileges. The packages copy pre-installation and post-installation shell scripts into a user-writable directory, letting a local user replace code later run by the installer. Exploitation requires local access and installation of an affected package; successful commands run in the installer's higher-privileged context.

The record

CVE
CVE-2021-34409
Published
Sep 27, 2021
Updated
Sep 16, 2024
Vendor
Zoom Video Communications, Inc.
Product
Zoom Client Plugin for Sharing iPhone/iPad
Classifications
CWE-732, T1574
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <5.2.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Zoom Video Communications, Inc. · Zoom Client Plugin for Sharing iPhone/iPadversion=unspecified <5.2.0
Zoom Video Communications, Inc. · Zoom Rooms for Conference Roomversion=unspecified <5.1.0
Zoom Video Communications, Inc. · Zoom Client for Meetings for MacOSversion=unspecified <5.2.0

Published CVSS scores

7.8Zoom Video Communications, Inc.CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-732Incorrect Permission Assignment for Critical Resource
T1574Hijack Execution Flow

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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