Security Bulletin | Zoom (2023)

Description: Zoom Client for Meetings for macOS (Standard and for IT Admin) starting with 5.10.6 and prior to 5.12.0 contains a debugging port misconfiguration. When camera mode rendering context is enabled as part of the Zoom App Layers API by running certain Zoom Apps, a local debugging port is opened by the Zoom client. A local malicious user could use this debugging port to connect to and control the Zoom Apps running in the Zoom client.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: Zoom On-Premise Meeting Connector MMR before version 4.8.20220916.131 contains an improper access control vulnerability. As a result, a malicious actor in a meeting or webinar they are authorized to join could prevent participants from receiving audio and video causing meeting disruptions.

For Zoom On-Premise Deployments, IT administrators can help keep their Zoom software up-to-date by following this: https://support.zoom.us/hc/en-us/articles/360043960031

Description: Zoom On-Premise Meeting Connector MMR before version 4.8.20220815.130 contains an improper access control vulnerability. As a result, a malicious actor can join a meeting which they are authorized to join without appearing to the other participants.

For Zoom On-Premise Deployments, IT administrators can help keep their Zoom software up-to-date by following this: https://support.zoom.us/hc/en-us/articles/360043960031

Description: Zoom On-Premise Meeting Connector MMR before version 4.8.20220815.130 contains an improper access control vulnerability. As a result, a malicious actor could obtain the audio and video feed of a meeting they were not authorized to join and cause other meeting disruptions.

For Zoom On-Premise Deployments, IT administrators can help keep their Zoom software up-to-date by following this: https://support.zoom.us/hc/en-us/articles/360043960031

Description: The Zoom Client for Meetings for macOS (Standard and for IT Admin) starting with version 5.7.3 and before 5.11.6 contains a vulnerability in the auto update process. A local low-privileged user could exploit this vulnerability to escalate their privileges to root.

Note: This issue allows for a bypass of the patch issued in 5.11.5 to address CVE-2022-28756.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: The Zoom Client for Meetings for macOS (Standard and for IT Admin) starting with version 5.7.3 and before 5.11.5 and Zoom Rooms for Conference Room for macOS before version 5.11.6 contains a vulnerability in the auto update process. A local low-privileged user could exploit this vulnerability to escalate their privileges to root.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

*Changes - 2022-09-13 - Updated title, description and added Zoom Rooms to the “Affected Products” section.

Description: The Zoom Client for Meetings for macOS (Standard and for IT Admin) before version 5.11.3 contain a vulnerability in the package signature validation during the update process. A local low-privileged user could exploit this vulnerability to escalate their privileges to root.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: Zoom On-Premise Meeting Connector MMR before version 4.8.129.20220714 contains an improper access control vulnerability. As a result, a malicious actor can join a meeting which they are authorized to join without appearing to the other participants, can admit themselves into the meeting from the waiting room, and can become host and cause other meeting disruptions.

For Zoom On-Premise Deployments, IT administrators can help keep their Zoom software up-to-date by following this: https://support.zoom.us/hc/en-us/articles/360043960031

Description: 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.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: Zoom Rooms for Conference Rooms for Windows versions before 5.11.0 are susceptible to a Local Privilege Escalation vulnerability. A local low-privileged malicious user could exploit this vulnerability to escalate their privileges to the SYSTEM user.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: Zoom On-Premise Meeting Connector Zone Controller (ZC) before version 4.8.20220419.112 fails to properly parse STUN error codes, which can result in memory corruption and could allow a malicious actor to crash the application. In versions older than 4.8.12.20211115, this vulnerability could also be leveraged to execute arbitrary code.

For Zoom On-Premise Deployments, IT administrators can help keep their Zoom software up-to-date by following this guidance:
https://support.zoom.us/hc/en-us/articles/360043960031

Description: Zoom’s On-Premise Meeting Connector MMR before version 4.8.113.20220526 fails to properly check the permissions of a Zoom meeting attendee. As a result, a threat actor in the Zoom’s waiting room can join the meeting without the consent of the host.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: The Zoom Opener installer is downloaded by a user from the Launch meeting page, when attempting to join a meeting without having the Zoom Meeting Client installed. The Zoom Opener installer for Zoom Client for Meetings before version 5.10.3 and Zoom Rooms for Conference Room for Windows before version 5.10.3 are susceptible to a DLL injection attack. This vulnerability could be used to run arbitrary code on the victim’s host.

Users can help keep themselves secure by removing older versions of the Zoom Opener installer and running the latest version of the Zoom Opener installer from the “Download Now" button on the "Launch Meeting" page. User’s can also protect themselves by downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: The Zoom Client for Meetings (for Android, iOS, Linux, macOS, and Windows) before version 5.10.0 fails to properly validate the hostname during a server switch request. This issue could be used in a more sophisticated attack to trick an unsuspecting user’s client to connect to a malicious server when attempting to use Zoom services.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: The Zoom Client for Meetings for Windows before version 5.10.0 and Zoom Rooms for Conference Room for Windows before version 5.10.0, fails to properly check the installation version during the update process. This issue could be used in a more sophisticated attack to trick a user into downgrading their Zoom client to a less secure version.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: The Zoom Client for Meetings (for Android, iOS, Linux, macOS, and Windows) before version 5.10.0 fails to properly constrain client session cookies to Zoom domains. This issue could be used in a more sophisticated attack to send a user’s Zoom-scoped session cookies to a non-Zoom domain. This could potentially allow for spoofing of a Zoom user.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: The Zoom Client for Meetings (for Android, iOS, Linux, macOS, and Windows) before version 5.10.0 fails to properly parse XML stanzas in XMPP messages. This can allow a malicious user to break out of the current XMPP message context and create a new message context to have the receiving user’s client perform a variety of actions. This issue could be used in a more sophisticated attack to forge XMPP messages from the server.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: A vulnerability in Zoom On-Premise Meeting Connector Controller version 4.8.102.20220310 and On-Premise Meeting Connector MMR version 4.8.102.20220310 exposes process memory fragments to connected clients, which could be observed by a passive attacker.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates.

Description: The Zoom Client for Meetings for Windows prior to version 5.9.7, Zoom Rooms for Conference Room for Windows prior to version 5.10.0, Zoom Plugins for Microsoft Outlook for Windows prior to version 5.10.3, and Zoom VDI Windows Meeting Clients prior to version 5.9.6; was susceptible to a local privilege escalation issue during the installer repair operation. A malicious actor could utilize this to potentially delete system level files or folders, causing integrity or availability issues on the user’s host machine.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: The Zoom Client for Meetings for macOS (Standard and for IT Admin) prior to version 5.9.6 failed to properly check the package version during the update process. This could lead to a malicious actor updating an unsuspecting user’s currently installed version to a less secure version.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: The Zoom Client for Meetings chat functionality was susceptible to Zip bombing attacks in the following product versions: Android before version 5.8.6, iOS before version 5.9.0, Linux before version 5.8.6, macOS before version 5.7.3, and Windows before version 5.6.3. This could lead to availability issues on the client host by exhausting system resources.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: The Keybase Clients for macOS and Windows before version 5.9.0 fails to properly remove exploded messages initiated by a user. This can occur if the receiving user switches to a non-chat feature and places the host in a sleep state before the sending user explodes the messages. This could lead to disclosure of sensitive information which was meant to be deleted from a user’s filesystem.

Users can help keep themselves secure by applying current updates or downloading the latest Keybase software with all current security updates from https://keybase.io/download.

Description: A vulnerability was discovered in the Keybase Client for Windows before version 5.6.0 when a user executed the "keybase git lfs-config" command on the command-line. In versions prior to 5.6.0, a malicious actor with write access to a user’s Git repository could leverage this vulnerability to potentially execute arbitrary Windows commands on a user’s local system.

Users can help keep themselves secure by applying current updates or downloading the latest Keybase software with all current security updates from https://keybase.io/download.

Description: The Zoom Client for Meetings before version 5.7.3 (for Android, iOS, Linux, macOS, and Windows) contain a server side request forgery vulnerability in the chat’s “link preview” functionality. In versions prior to 5.7.3, if a user were to enable the chat’s “link preview” feature, a malicious actor could trick the user into potentially sending arbitrary HTTP GET requests to URLs that the actor cannot reach directly.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: A vulnerability was discovered in the products listed in the "Affected Products" section of this bulletin which potentially allowed for the exposure of the state of process memory. This issue could be used to potentially gain insight into arbitrary areas of the product’s memory.

Zoom has addressed this issue in the latest releases of the products listed in the section below. Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates.

Description: A buffer overflow vulnerability was discovered in the products listed in the “Affected Products'' section of this bulletin. This can potentially allow a malicious actor to crash the service or application, or leverage this vulnerability to execute arbitrary code.

Zoom has addressed this issue in the latest releases of the products listed in the section below. Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates.

Description: The Keybase Client for Windows before version 5.7.0 contains a path traversal vulnerability when checking the name of a file uploaded to a team folder. A malicious user could upload a file to a shared folder with a specially crafted file name which could allow a user to execute an application which was not intended on their host machine. If a malicious user leveraged this issue with the public folder sharing feature of the Keybase client, this could lead to remote code execution.

Keybase addressed this issue in the 5.7.0 Keybase Client for Windows release. Users can help keep themselves secure by applying current updates or downloading the latest Keybase software with all current security updates from https://keybase.io/download.

Description: The Keybase Client for Android before version 5.8.0 and the Keybase Client for iOS before version 5.8.0 fails to properly remove exploded messages initiated by a user if the receiving user places the chat session in the background while the sending user explodes the messages. This could lead to disclosure of sensitive information which was meant to be deleted from the customer’s device.

Keybase addressed this issue in the 5.8.0 Keybase Client for Android and the 5.8.0 Keybase Client for iOS releases. Users can help keep themselves secure by applying current updates or downloading the latest Keybase software with all current security updates from https://keybase.io/download.

Description: The Zoom Client for Meetings for Windows installer before version 5.5.4 does not properly verify the signature of files with .msi, .ps1, and .bat extensions. This could lead to a malicious actor installing malicious software on a customer’s computer.

Zoom addressed this issue in the 5.5.4 Zoom Client for Meetings for Windows release. Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: In the Zoom Client for Meetings for Ubuntu Linux before version 5.1.0, there is an HTML injection flaw when sending a remote control request to a user in the process of in-meeting screen sharing. This could allow meeting participants to be targeted for social engineering attacks.

Zoom addressed this issue in the 5.1.0 Zoom Client for Meetings for Ubuntu Linux release. Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download

Description: During the installation process for all versions of the Zoom Client for Meetings for Windows before 5.4.0, it is possible to launch Internet Explorer. If the installer was launched with elevated privileges such as by SCCM this can result in a local privilege escalation.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: During the installation process forZoom Rooms for Conference Room for Windows before version 5.3.0 it is possible to launch Internet Explorer with elevated privileges. If the installer was launched with elevated privileges such as by SCCM this can result in a local privilege escalation.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: It was discovered that the installation packages of the Zoom Client for Meetings for macOS (Standard and for IT Admin) installation before version 5.2.0, Zoom Client Plugin for Sharing iPhone/iPad before version 5.2.0, and Zoom Rooms for Conference before version 5.1.0, copy pre- and post- installation shell scripts to a user-writable directory. In the affected products listed below, a malicious actor with local access to a user's machine could use this flaw to potentially run arbitrary system commands in a higher privileged context during the installation process.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

*Changes - 2021-12-14 - Updated description, updated CVSS score, updated CVSS vector string, added Zoom Client Plugin for Sharing iPhone/iPad and Zoom Rooms to the “Affected Products” section.

Description: A user-writable directory created during the installation of the Zoom Client for Meetings for Windows version prior to version 5.3.2 can be redirected to another location using a junction. This would allow an attacker to overwrite files that a limited user would otherwise be unable to modify.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: The Zoom Client for Meetings for Windows in all versions before 5.3.0 fails to properly validate the certificate information used to sign .msi files when performing an update of the client. This could lead to remote code execution in an elevated privileged context.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: A heap based buffer overflow exists in all desktop versions of the Zoom Client for Meetings before version 5.6.3. This Finding was reported to Zoom as a part of 2021 Pwn20wn Vancouver. The attack chain demonstrated during Pwn20wn was mitigated in a server-side change in Zoom’s infrastructure on 2021-04-09.

When combined with two other issues reported during Pwn20wn - improper URL validation when sending an XMPP message to access a Zoom Marketplace app URL and incorrect URL validation when displaying a GIPHY image - a malicious user can achieve remote code execution on a target’s computer.
The target must have previously accepted a Connection Request from the malicious user or be in a multi-user chat with the malicious user for this attack to succeed. The attack chain demonstrated in Pwn20wn can be highly visible to targets, causing multiple client notifications to occur.

Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: A vulnerability affected the Zoom Windows and Linux Clients’ share screen functionality when sharing individual application windows, in which screen contents of applications which are not explicitly shared by the screen-sharing users may be seen by other meeting participants for a brief moment if the “sharer” is minimizing, maximizing, or closing another window.

Zoom introduced several new security mitigations in Zoom Windows Client version 5.6 that reduce the possibility of this issue occurring for Windows users. We are continuing to work on additional measures to resolve this issue across all affected platforms.

Zoom also resolved the issue for Ubuntu users on March 1, 2021 in Zoom Linux Client version 5.5.4. Users can apply current updates or download the latest Zoom software with all current security updates from https://zoom.us/download.

Description: A vulnerability related to Dynamic-link Library (“DLL”) loading in the Zoom Sharing Service could allow a local Windows user to escalate privileges to those of the NT AUTHORITY/SYSTEM user.

The vulnerability is due to insufficient signature checks of dynamically loaded DLLs when loading a signed executable. An attacker could exploit this vulnerability by injecting a malicious DLL into a signed Zoom executable and using it to launch processes with elevated permissions.

Zoom addressed this issue in the 5.0.4 client release. Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: A vulnerability in how the Zoom Windows installer handles junctions when deleting files could allow a local Windows user to delete files otherwise not deletable by the user.

The vulnerability is due to insufficient checking for junctions in the directory from which the installer deletes files, which is writable by standard users. A malicious local user could exploit this vulnerability by creating a junction in the affected directory that points to protected system files or other files to which the user does not have permissions. Upon running the Zoom Windows installer with elevated permissions, as is the case when it is run through managed deployment software, those files would get deleted from the system.

Zoom addressed this issue in the 4.6.10 client release. Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: A vulnerability in the Zoom macOS client could allow an attacker to download malicious software to a victim's device.

The vulnerability is due to improper input validation and validation of downloaded software in the ZoomOpener helper application. An attacker could exploit the vulnerability to prompt a victim's device to download files on the attacker's behalf. A successful exploit is only possible if the victim previously uninstalled the Zoom Client.

Zoom addressed this issue in the 4.4.52595.0425 client release. Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: A vulnerability in the macOS Zoom and RingCentral clients could allow a remote, unauthenticated attacker to force a user to join a video call with the video camera active.

The vulnerability is due to insufficient authorization controls to check which systems may communicate with the local Zoom Web server running on port 19421. An attacker could exploit this vulnerability by creating a malicious website that causes the Zoom client to automatically join a meeting set up by the attacker.

Zoom implemented a new Video Preview dialog that is presented to the user before joining a meeting in Client version 4.4.5 published July 14, 2019. This dialog enables the user to join the meeting with or without video enabled and requires the user to set their desired default behavior for video. Zoom urges customers to install the latest Zoom Client release available at https://zoom.us/download.

Description: A vulnerability in the macOS Zoom client could allow a remote, unauthenticated attacker to trigger a denial-of-service condition on a victim's system.

The vulnerability is due to insufficient authorization controls to check which systems may communicate with the local Zoom Web server running on port 19421. An attacker could exploit this vulnerability by creating a malicious website that causes the Zoom client to repeatedly try to join a meeting with an invalid meeting ID. The infinite loop causes the Zoom client to become inoperative and can impact performance of the system on which it runs.

Zoom released version 4.4.2-hotfix of the macOS client on April 28, 2019 to address the issue. Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.

Description: A vulnerability in the Zoom client could allow a remote, unauthenticated attacker to control meeting functionality such as ejecting meeting participants, sending chat messages, and controlling participant microphone muting. If the attacker was also a valid participant in the meeting and another participant was sharing their desktop screen, the attacker could also take control of that participant’s keyboard and mouse.

The vulnerability is due to the fact that Zoom's internal messaging pump dispatched both client User Datagram Protocol (UDP) and server Transmission Control Protocol (TCP) messages to the same message handler. An attacker can exploit this vulnerability to craft and send UDP packets which get interpreted as messages processed from the trusted TCP channel used by authorized Zoom servers.

Zoom released client updates to address this security vulnerability. Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download.