CVE-2021-28133Public exploitNetwork attack vector

Information disclosure via miscomposited application windows

Published Mar 18, 2021 · Updated Aug 3, 2024

Information disclosure in Zoom Windows and Linux Clients allows remote authenticated users to view unshared window contents during meetings. The application-window sharing path briefly composites a different foreground window into outgoing video when it overlays the shared window during minimize, maximize, or close operations. Exploitation requires the target to share one application window in a meeting while another crosses it; a participant can preserve exposed frames with screen recording.

CVSS severity5.7
Medium
EPSS probability16.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Zoom Windows and Linux Clients allows remote authenticated users to view unshared window contents during meetings. The application-window sharing path briefly composites a different foreground window into outgoing video when it overlays the shared window during minimize, maximize, or close operations. Exploitation requires the target to share one application window in a meeting while another crosses it; a participant can preserve exposed frames with screen recording.

The record

CVE
CVE-2021-28133
Published
Mar 18, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-668, T1113
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 18, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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 vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.7ZoomCVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-668Exposure of Resource to Wrong Sphere
T1113Screen Capture

Public exploit references

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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