Zoom Client for Meetings < 5.6.3 Vulnerability (ZSB-21002)

high Nessus Plugin ID 168816


The remote host has an application installed that is affected by a vulnerability.


The version of Zoom Client for Meetings installed on the remote host is prior to 5.6.3. It is, therefore, affected by a vulnerability as referenced in the ZSB-21002 advisory.

- 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. (CVE-2021-30480)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.


Upgrade to Zoom Client for Meetings 5.6.3 or later.

See Also


Plugin Details

Severity: High

ID: 168816

File Name: zoom_client_ZSB-21002.nasl

Version: 1.4

Type: local

Agent: windows, macosx, unix

Family: Misc.

Published: 12/15/2022

Updated: 9/15/2023

Supported Sensors: Nessus Agent

Risk Information


Risk Factor: Medium

Score: 6.7


Risk Factor: High

Base Score: 9

Temporal Score: 7

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2021-30480


Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:zoom:zoom, cpe:/a:zoom:meetings

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 8/13/2021

Vulnerability Publication Date: 8/13/2021

Reference Information

CVE: CVE-2021-30480