CVE-2021-34423
In your normal cycle
Critical by CVSS (9.8), but no sign of active exploitation.
Description
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.
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 3.27% — more likely to be exploited than 88% of all CVEs |
| Weakness | CWE-120 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2021-11-24 |
| Last modified | 2026-06-17 |
Affected (31)
| Vendor | Product |
|---|---|
| apple | iphone os |
| apple | macos |
| android | |
| linux | linux kernel |
| microsoft | windows |
| zoom | android meeting sdk |
| zoom | android video sdk |
| zoom | controllers for zoom rooms |
| zoom | hybrid mmr |
| zoom | hybrid zproxy |
| zoom | iphone os meeting sdk |
| zoom | iphone os video sdk |
| zoom | macos meeting sdk |
| zoom | macos video sdk |
| zoom | meetings |
| zoom | meetings for blackberry |
| zoom | meetings for chrome os |
| zoom | meetings for intune |
| zoom | rooms for conference rooms |
| zoom | vdi azure virtual desktop |
| zoom | vdi citrix |
| zoom | vdi vmware |
| zoom | vdi windows meeting client |
| zoom | virtual desktop infrastructure |
| zoom | windows meeting sdk |
| zoom | windows video sdk |
| zoom | zoom on-premise meeting connector controller |
| zoom | zoom on-premise meeting connector mmr |
| zoom | zoom on-premise recording connector |
| zoom | zoom on-premise virtual room connector |
| zoom | zoom on-premise virtual room connector load balancer |
References
- http://packetstormsecurity.com/files/165417/Zoom-Chat-Message-Processing-Buffer-Overflow.html
- https://explore.zoom.us/en/trust/security/security-bulletin
- http://packetstormsecurity.com/files/165417/Zoom-Chat-Message-Processing-Buffer-Overflow.html
- https://explore.zoom.us/en/trust/security/security-bulletin
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