Home/CVE/A buffer overflow vulnerability was discovered in Zoom Client for Meetings (for Android, iOS, Linux, macOS, and Windows)
CVE

CVE-2021-34423

A buffer overflow vulnerability was discovered in Zoom Client for Meetings (for Android, iOS, Linux, macOS, and Windows)

A buffer overflow vulnerability was discovered in Zoom Client for Meetings (for Android, iOS, Linux, macOS, and Windows) before version 5.8.4, Zoom Client for Meetings for Blackberry (for Android and iOS) before version 5.8.1, Zoom Client for Meetings for intune (for Android and iOS) before version 5.8.4, Zoom Client for Meetings for Chrome OS before version 5.0.1, Zoom Rooms for Conference Room (for Android, AndroidBali, macOS, and Windows) before version 5.8.3, Controllers for Zoom Rooms (for Android, iOS, and Windows) before version 5.8.3, Zoom VDI Windows Meeting Client before version 5.8.4, Zoom VDI Azure Virtual Desktop Plugins (for Windows x86 or x64, IGEL x64, Ubuntu x64, HP ThinPro OS x64) before version 5.8.4.21112, Zoom VDI Citrix Plugins (for Windows x86 or x64, Mac Universal Installer & Uninstaller, IGEL x64, eLux RP6 x64, HP ThinPro OS x64, Ubuntu x64, CentOS x 64, Dell ThinOS) before version 5.8.4.21112, Zoom VDI VMware Plugins (for Windows x86 or x64, Mac Universal Installer & Uninstaller, IGEL x64, eLux RP6 x64, HP ThinPro OS x64, Ubuntu x64, CentOS x 64, Dell ThinOS) before version 5.8.4.21112, Zoom Meeting SDK for Android before version 5.7.6.1922, Zoom Meeting SDK for iOS before version 5.7.6.1082, Zoom Meeting SDK for macOS before version 5.7.6.1340, Zoom Meeting SDK for Windows before version 5.7.6.1081, Zoom Video SDK (for Android, iOS, macOS, and Windows) before version 1.1.2, Zoom On-Premise Meeting Connector Controller before version 4.8.12.20211115, Zoom On-Premise Meeting Connector MMR before version 4.8.12.20211115, Zoom On-Premise Recording Connector before version 5.1.0.65.20211116, Zoom On-Premise Virtual Room Connector before version 4.4.7266.20211117, Zoom On-Premise Virtual Room Connector Load Balancer before version 2.5.5692.20211117, Zoom Hybrid Zproxy before version 1.0.1058.20211116, and Zoom Hybrid MMR before version 4.6.20211116.131_x86-64. This can potentially allow a malicious actor to crash the service or application, or leverage this vulnerability to execute arbitrary code.

CRITICAL · CVSS 9.8 EPSS 0.00387
Act now
  • Public exploit or PoC is available
  • CVSS base score ≥ 7.0
Sigma rules8 YARA rules0
⬡

Weakness Classification

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
▤

Affected Products & Versions

27
zoom meetings< 5.8.3
zoom meetings< 5.8.4
zoom meetings for blackberry< 5.8.1
zoom meetings for intune< 5.8.4
zoom meetings for chrome os< 5.0.1
zoom rooms for conference rooms< 5.8.3
zoom controllers for zoom rooms< 5.8.3
zoom virtual desktop infrastructure< 5.8.4
⚠

Public Exploits & PoCs

1
pocpacketstormsecurity.com · Zoom-Chat-Message-Processing-Buffer-Overflow.htmlpacketstormsecurity.com
◈

Sigma Hunt Rules

8
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
producthighSuspicious Microsoft Office Child Process - MacOS
producthighRemote Access Tool - Renamed MeshAgent Execution - MacOS
producthighBinary Padding - MacOS
productmediumSuspicious Execution via macOS Script Editor
productmediumSystem Information Discovery Via Sysctl - MacOS
productmediumNew File Exclusion Added To Time Machine Via Tmutil - MacOS
▣

Scoring & Timeline

9.8
CRITICAL · CVSS v3.1 · security@zoom.us
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD24 Nov 2021 · 05:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
🔗

References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://explore.zoom.us/en/trust/security/security-bulletinVendor Advisory
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