# Buffer overflow in Zoom client and other products CVE record · `CVE-2021-34423` - **Identifiers:** `CVE-2021-34423` - **State:** Confirmed - **Severity:** CVSS 7.3 High - **Critical:** No - **CNA:** Zoom - **Technologies:** [Zoom Video Communications Inc Zoom Client for Meetings (for Android, iOS, Linux, macOS, and Windows)](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-client-for-meetings-for-android-ios-linux-mac.md) · [Zoom Video Communications Inc Zoom Client for Meetings for Blackberry (for Android and iOS)](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-client-for-meetings-for-blackberry-for-androi.md) · [Zoom Video Communications Inc Zoom Client for Meetings for intune (for Android and iOS)](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-client-for-meetings-for-intune-for-android-an.md) · [Zoom Video Communications Inc Zoom Client for Meetings for Chrome OS](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-client-for-meetings-for-chrome-os.md) · [Zoom Video Communications Inc Zoom Rooms for Conference Room (for Android, AndroidBali, macOS, and Windows)](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-rooms-for-conference-room-for-android-android.md) · [Zoom Video Communications Inc Controllers for Zoom Rooms (for Android, iOS, and Windows)](https://agentprime.io/advisories/technology/zoom-video-communications-inc-controllers-for-zoom-rooms-for-android-ios-and-win.md) · [Zoom Video Communications Inc Zoom VDI Windows Meeting Client](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-vdi-windows-meeting-client.md) · [Zoom Video Communications Inc Zoom VDI Azure Virtual Desktop Plugins (for Windows x86 or x64, IGEL x64, Ubuntu x64, HP ThinPro OS x64)](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-vdi-azure-virtual-desktop-plugins-for-windows.md) · [Zoom Video Communications Inc 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)](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-vdi-citrix-plugins-for-windows-x86-or-x64-mac.md) · [Zoom Video Communications Inc 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)](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-vdi-vmware-plugins-for-windows-x86-or-x64-mac.md) · [Zoom Video Communications Inc Zoom Meeting SDK for Android](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-meeting-sdk-for-android.md) · [Zoom Video Communications Inc Zoom Meeting SDK for iOS](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-meeting-sdk-for-ios.md) · [Zoom Video Communications Inc Zoom Meeting SDK for macOS](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-meeting-sdk-for-macos.md) · [Zoom Video Communications Inc Zoom Meeting SDK for Windows](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-meeting-sdk-for-windows.md) · [Zoom Video Communications Inc Zoom Video SDK (for Android, iOS, macOS, and Windows)](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-video-sdk-for-android-ios-macos-and-windows.md) · [Zoom Video Communications Inc Zoom On-Premise Meeting Connector Controller](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-on-premise-meeting-connector-controller.md) · [Zoom Video Communications Inc Zoom On-Premise Meeting Connector MMR](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-on-premise-meeting-connector-mmr.md) · [Zoom Video Communications Inc Zoom On-Premise Recording Connector](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-on-premise-recording-connector.md) · [Zoom Video Communications Inc Zoom On-Premise Virtual Room Connector](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-on-premise-virtual-room-connector.md) · [Zoom Video Communications Inc Zoom On-Premise Virtual Room Connector Load Balancer](https://agentprime.io/advisories/technology/zoom-video-communications-inc-zoom-on-premise-virtual-room-connector-load-balanc.md) - **Published:** 24 Nov 2021 - **Updated:** 17 Sept 2024 - **Reviewed by a person:** No Published by the CVE Program (CNA: Zoom) at 24 Nov 2021, 16:53 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. ## Affected products, as the CNA wrote them - Vendor: Zoom Video Communications Inc. Product: Zoom Client for Meetings (for Android, iOS, Linux, macOS, and Windows). - affected: `unspecified to before 5.8.4` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom Client for Meetings for Blackberry (for Android and iOS). - affected: `unspecified to before 5.8.1` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom Client for Meetings for intune (for Android and iOS). - affected: `unspecified to before 5.8.4` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom Client for Meetings for Chrome OS. - affected: `unspecified to before 5.0.1` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom Rooms for Conference Room (for Android, AndroidBali, macOS, and Windows). - affected: `unspecified to before 5.8.3` (custom) - Vendor: Zoom Video Communications Inc. Product: Controllers for Zoom Rooms (for Android, iOS, and Windows). - affected: `unspecified to before 5.8.3` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom VDI Windows Meeting Client. - affected: `unspecified to before 5.8.4` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom VDI Azure Virtual Desktop Plugins (for Windows x86 or x64, IGEL x64, Ubuntu x64, HP ThinPro OS x64). - affected: `unspecified to before 5.8.4.21112` (custom) - Vendor: Zoom Video Communications Inc. Product: 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). - affected: `unspecified to before 5.8.4.21112` (custom) - Vendor: Zoom Video Communications Inc. Product: 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). - affected: `unspecified to before 5.8.4.21112` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom Meeting SDK for Android. - affected: `unspecified to before 5.7.6.1922` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom Meeting SDK for iOS. - affected: `unspecified to before 5.7.6.1082` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom Meeting SDK for macOS. - affected: `unspecified to before 5.7.6.1340` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom Meeting SDK for Windows. - affected: `unspecified to before 5.7.6.1081` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom Video SDK (for Android, iOS, macOS, and Windows). - affected: `unspecified to before 1.1.2` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom On-Premise Meeting Connector Controller. - affected: `unspecified to before 4.8.12.20211115` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom On-Premise Meeting Connector MMR. - affected: `unspecified to before 4.8.12.20211115` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom On-Premise Recording Connector. - affected: `unspecified to before 5.1.0.65.20211116` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom On-Premise Virtual Room Connector. - affected: `unspecified to before 4.4.7266.20211117` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom On-Premise Virtual Room Connector Load Balancer. - affected: `unspecified to before 2.5.5692.20211117` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom Hybrid Zproxy. - affected: `unspecified to before 1.0.1058.20211116` (custom) - Vendor: Zoom Video Communications Inc. Product: Zoom Hybrid MMR. - affected: `unspecified to before 4.6.20211116.131_x86-64` (custom) ## Not analysed yet We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter. ## Severity and exploitation - 7.3 High, CVSS 3.0: `CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L`, from CNA (Zoom) - **CISA KEV:** Not listed. - **EPSS:** 0.033, the 88th percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline This record came from the full history of the CVE Program, published 24 Nov 2021. New records show when each source confirmed them. ## Sources - [CVE List: CVE-2021-34423](https://www.cve.org/CVERecord?id=CVE-2021-34423) - [NVD: CVE-2021-34423](https://nvd.nist.gov/vuln/detail/CVE-2021-34423) ### References from the CNA - - Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description. ## Check whether this affects you This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run. - With the agentprime MCP server (), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: - As JSON: - Everything that needs attention now: --- The web page: . Everything for agents: .