CVE-2021-34420

Zoom Windows installation executable signature bypass

Severity Score

7.4

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

El instalador de Zoom Client for Meetings para Windows anterior a la versión 5.5.4 no verifica correctamente la firma de los archivos con extensiones .msi, .ps1 y .bat. Esto podría dar lugar a que un actor malintencionado instalara software malicioso en el ordenador de un cliente

*Credits: Laurent Delosieres of ManoMano

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

None

Integrity

High

Availability

None

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

None

Integrity

Low

Availability

None

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

None

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-06-09 CVE Reserved
2021-11-11 CVE Published
2024-07-28 EPSS Updated
2024-09-16 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-347: Improper Verification of Cryptographic Signature

CAPEC

References (2)

URL	Tag	Source
https://medium.com/manomano-tech/a-red-team-operation-leveraging-a-zero-day-vulnerability-in-zoom-80f57fb0822e	Third Party Advisory

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://explore.zoom.us/en/trust/security/security-bulletin	2021-12-16

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Zoom Search vendor "Zoom"		Zoom Client For Meetings Search vendor "Zoom" for product "Zoom Client For Meetings"				< 5.4.4 Search vendor "Zoom" for product "Zoom Client For Meetings" and version " < 5.4.4"		windows		Affected