Zoom clients before version 5.13.5 contain a STUN parsing vulnerability. A malicious actor could send specially crafted UDP traffic to a victim Zoom client to remotely cause the client to crash, causing a denial of service.

The Zoom Client for Meetings (for Android, iOS, Linux, macOS, and Windows) before version 5.11.0 are susceptible to a URL parsing vulnerability. If a malicious Zoom meeting URL is opened, the malicious link may direct the user to connect to an arbitrary network address, leading to additional attacks including the potential for remote code execution through launching executables from arbitrary paths.

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.

The Zoom Client before 4.4.53932.0709 on macOS allows remote code execution, a different vulnerability than CVE-2019-13450. If the ZoomOpener daemon (aka the hidden web server) is running, but the Zoom Client is not installed or can't be opened, an attacker can remotely execute code with a maliciously crafted launch URL. NOTE: ZoomOpener is removed by the Apple Malware Removal Tool (MRT) if this tool is enabled and has the 2019-07-10 MRTConfigData.