CVE-2020-9399 : Exploit Details and Defense Strategies

A vulnerability in the Avast AV parsing engine allows a virus-detection bypass via a crafted ZIP archive.

Understanding CVE-2020-9399

What is CVE-2020-9399?

The Avast AV parsing engine vulnerability enables attackers to bypass virus detection using a specially crafted ZIP archive. This vulnerability impacts versions before 12 definitions 200114-0 of Antivirus Pro, Antivirus Pro Plus, and Antivirus for Linux.

The Impact of CVE-2020-9399

This vulnerability could allow malicious actors to evade detection by antivirus software, potentially leading to successful malware execution and compromise of systems.

Technical Details of CVE-2020-9399

Vulnerability Description

The flaw in the Avast AV parsing engine permits threat actors to bypass virus detection mechanisms by exploiting a specifically crafted ZIP archive.

Affected Systems and Versions

Versions before 12 definitions 200114-0 of Antivirus Pro, Antivirus Pro Plus, and Antivirus for Linux are vulnerable.

Exploitation Mechanism

The vulnerability can be exploited by creating a malicious ZIP archive that tricks the Avast AV parsing engine, allowing malware to evade detection.

Mitigation and Prevention

Immediate Steps to Take

Update Avast Antivirus to the latest version that includes patches for CVE-2020-9399.
Avoid opening ZIP archives from untrusted or unknown sources.
Implement additional security measures such as network segmentation and endpoint protection.

Long-Term Security Practices

Regularly update antivirus software and security patches to protect against known vulnerabilities.
Conduct security awareness training to educate users on identifying and avoiding malicious files.

Patching and Updates

Ensure timely installation of security updates and patches provided by Avast to address the CVE-2020-9399 vulnerability.