← Vulnerability feed

Vulnerability record · CVE-2021-28133 · published 18 March 2021

CVE-2021-28133: Zoom information exposure vulnerability

Zoom · Zoom

Zoom through 5.5.4 sometimes allows attackers to read private information on a participant's screen, even though the participant never attempted to share the private part of their screen. When a user shares a specific application window via the Share Screen functionality, other meeting participants can briefly see contents of other application windows that were explicitly not shared. The contents of these other windows can (for instance) be seen for a short period of time when they overlay the shared window and get into focus. (An attacker can, of course, use a separate screen-recorder application, unsupported by Zoom, to save all such contents for later replays and analysis.) Depending on the unintentionally shared data, this short exposure of screen contents may be a more or less severe security issue.

4.3 CVSS 3.1 Medium EPSS 16% · top 3.2% CWE-200 · Information exposure
4.3CVSS 3.1 base score, v2 4.3
16%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
14References
17 Jun 2026Last modified by NVD

Description

Zoom through 5.5.4 sometimes allows attackers to read private information on a participant's screen, even though the participant never attempted to share the private part of their screen. When a user shares a specific application window via the Share Screen functionality, other meeting participants can briefly see contents of other application windows that were explicitly not shared. The contents of these other windows can (for instance) be seen for a short period of time when they overlay the shared window and get into focus. (An attacker can, of course, use a separate screen-recorder application, unsupported by Zoom, to save all such contents for later replays and analysis.) Depending on the unintentionally shared data, this short exposure of screen contents may be a more or less severe security issue.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://packetstormsecurity.com/files/161897/Zoom-5.4.3-54779.1115-5.5.4-13142.0301-Information-Disclosure.html Third Party Advisory
http://seclists.org/fulldisclosure/2021/Mar/48 Third Party Advisory
https://thehackernews.com/2021/03/new-zoom-screen-sharing-bug-lets-other.html Third Party Advisory
https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2020-044.txt Third Party Advisory
https://www.syss.de/pentest-blog/syss-2020-044-sicherheitsproblem-in-screen-sharing-funktionalitaet-von-zoom-cve-2021-28 Third Party Advisory
https://www.youtube.com/watch?v=SonmmgQlLzg Third Party Advisory
https://zoom.us/trust/security/security-bulletin Vendor Advisory
http://packetstormsecurity.com/files/161897/Zoom-5.4.3-54779.1115-5.5.4-13142.0301-Information-Disclosure.html Third Party Advisory
http://seclists.org/fulldisclosure/2021/Mar/48 Third Party Advisory
https://thehackernews.com/2021/03/new-zoom-screen-sharing-bug-lets-other.html Third Party Advisory
https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2020-044.txt Third Party Advisory
https://www.syss.de/pentest-blog/syss-2020-044-sicherheitsproblem-in-screen-sharing-funktionalitaet-von-zoom-cve-2021-28 Third Party Advisory
https://www.youtube.com/watch?v=SonmmgQlLzg Third Party Advisory
https://zoom.us/trust/security/security-bulletin Vendor Advisory

Track CVE-2021-28133 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2024-24691Zoom meeting software development kit vulnerabilityImproper input validation in Zoom Desktop Client for Windows, Zoom VDI Client for Windows, and Zoom Meeting SDK for Windows may allow an unauthentica…EPSS 1.7%9.8CVE-2023-39213Zoom virtual desktop infrastructure injection vulnerabilityImproper neutralization of special elements in Zoom Desktop Client for Windows and Zoom VDI Client before 5.15.2 may allow an unauthenticated user to…EPSS 1.4%9.8CVE-2023-39216Zoom vulnerabilityImproper input validation in Zoom Desktop Client for Windows before 5.14.7 may allow an unauthenticated user to enable an escalation of privilege via…EPSS 1.2%9.8CVE-2023-36534Zoom path traversal vulnerabilityPath traversal in Zoom Desktop Client for Windows before 5.14.7 may allow an unauthenticated user to enable an escalation of privilege via network ac…EPSS 1.6%9.8CVE-2020-6109Zoom path traversal vulnerabilityAn exploitable path traversal vulnerability exists in the Zoom client, version 4.6.10 processes messages including animated GIFs. A specially crafted…EPSS 4.7%9.8CVE-2018-15715Zoom authentication bypass by spoofing vulnerabilityZoom clients on Windows (before version 4.1.34814.1119), Mac OS (before version 4.1.34801.1116), and Linux (2.4.129780.0915 and below) are vulnerable…EPSS 3.5%8.8CVE-2023-43586Zoom meeting software development kit untrusted search path vulnerabilityPath traversal in Zoom Desktop Client for Windows, Zoom VDI Client for Windows, and Zoom SDKs for Windows may allow an authenticated user to conduct …EPSS 0.99%8.8CVE-2023-43582Zoom meetings improper authentication vulnerabilityImproper authorization in some Zoom clients may allow an authorized user to conduct an escalation of privilege via network access.EPSS 0.66%

Source: NIST National Vulnerability Database (record CVE-2021-28133), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.