CVE-2020-3955 : What You Need to Know

ESXi 6.5 and 6.7 by VMware are affected by a Stored Cross-Site-Scripting vulnerability that allows script-related HTML to be executed when viewing virtual machine attributes.

Understanding CVE-2020-3955

What is CVE-2020-3955?

CVE-2020-3955 is a vulnerability in ESXi 6.5 and 6.7 without specific patches that fail to neutralize script-related HTML, leading to a Stored Cross-Site-Scripting (XSS) risk.

The Impact of CVE-2020-3955

This vulnerability has been rated as Important by VMware, with a maximum CVSSv3 base score of 8.3, signifying a significant security threat.

Technical Details of CVE-2020-3955

Vulnerability Description

ESXi 6.5 and 6.7 without the necessary patches do not properly neutralize script-related HTML, enabling Stored Cross-Site-Scripting attacks.

Affected Systems and Versions

Product: ESXi
Vendor: VMware
Affected Versions: ESXi 6.5 without patch ESXi650-201912104-SG, ESXi 6.7 without patch ESXi670-202004103-SG

Exploitation Mechanism

The vulnerability allows attackers to execute script-related HTML when accessing virtual machine attributes, potentially leading to unauthorized access and data manipulation.

Mitigation and Prevention

Immediate Steps to Take

Apply the recommended patches provided by VMware for ESXi 6.5 and 6.7 to mitigate the XSS vulnerability.
Regularly monitor VMware security advisories for updates and patches related to this issue.

Long-Term Security Practices

Implement strict input validation mechanisms to prevent XSS attacks in web applications.
Conduct regular security assessments and penetration testing to identify and address vulnerabilities proactively.

Patching and Updates

Ensure timely installation of security patches and updates released by VMware to address known vulnerabilities and enhance system security.