CVE-2021-34420 : What You Need to Know

Zoom Windows installation executable signature bypass is a vulnerability that affects Zoom Client for Meetings for Windows before version 5.5.4. It allows an attacker to install malicious software on a victim's computer by bypassing file signature verification.

Understanding CVE-2021-34420

What is CVE-2021-34420?

CVE-2021-34420, also known as Zoom Windows installation executable signature bypass, is a security vulnerability in Zoom Client for Meetings for Windows. It involves improper verification of cryptographic signature in the installer before version 5.5.4, potentially enabling a threat actor to install malicious software.

The Impact of CVE-2021-34420

The impact of CVE-2021-34420 is rated as medium severity, with a CVSS base score of 4.7. It can result in a malicious actor successfully installing unauthorized software on a target's system, compromising the integrity of the system.

Technical Details of CVE-2021-34420

Vulnerability Description

The vulnerability arises from the Zoom Client for Meetings for Windows installer failing to adequately verify the signature of files with .msi, .ps1, and .bat extensions. This oversight creates an avenue for an attacker to execute arbitrary code on a victim's machine.

Affected Systems and Versions

The specific version of Zoom affected by this vulnerability is any client for Windows prior to version 5.5.4. Users with older versions installed are at risk of exploitation.

Exploitation Mechanism

The exploit works by evading the signature check during the installation process, allowing an attacker to replace legitimate files with malicious ones, thus compromising the system.

Mitigation and Prevention

Immediate Steps to Take

Users are advised to update their Zoom Client for Meetings for Windows to version 5.5.4 or later to mitigate the vulnerability. It is crucial to only download software from official and verified sources to reduce the risk of malicious installations.

Long-Term Security Practices

In the long term, organizations and users should maintain a proactive approach to software security by regularly updating applications, implementing endpoint protection solutions, and educating users about safe software installation practices.

Patching and Updates

Zoom Video Communications Inc has released patches to address this vulnerability. Users should promptly apply these patches and stay vigilant for future security updates to protect their systems.