CVE-2024-39821

Installer denial of service via undisclosed race

Published Jul 15, 2024 · Updated Aug 2, 2024

TOCTOU race conditions in the Windows installers for Zoom Workplace Desktop App and Zoom Rooms App allow local users to interrupt installation. Zoom has not published which installer check and later use can be interleaved or what attacker-controlled state changes between them. Exploitation requires authenticated local access and user interaction; the published impact is denial of service, while Zoom's vector also records integrity loss.

CVSS severity6.6
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

TOCTOU race conditions in the Windows installers for Zoom Workplace Desktop App and Zoom Rooms App allow local users to interrupt installation. Zoom has not published which installer check and later use can be interleaved or what attacker-controlled state changes between them. Exploitation requires authenticated local access and user interaction; the published impact is denial of service, while Zoom's vector also records integrity loss.

The record

CVE
CVE-2024-39821
Published
Jul 15, 2024
Updated
Aug 2, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-367
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 15, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.6Zoom Video Communications, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:H
4.4NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/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-367Time-of-check Time-of-use (TOCTOU) Race Condition

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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