CVE-2020-3951 Explained : Impact and Mitigation

VMware Workstation (15.x before 15.5.2) and Horizon Client for Windows (5.x and prior before 5.4.0) contain a denial-of-service vulnerability due to a heap-overflow issue in Cortado Thinprint. Attackers with non-administrative access to a guest VM with virtual printing enabled may exploit this issue to create a denial-of-service condition of the Thinprint service running on the system where Workstation or Horizon Client is installed.

Understanding CVE-2020-3951

This CVE involves a denial-of-service vulnerability affecting VMware Workstation and Horizon Client for Windows.

What is CVE-2020-3951?

CVE-2020-3951 is a denial-of-service vulnerability in VMware Workstation and Horizon Client for Windows caused by a heap-overflow issue in Cortado Thinprint.

The Impact of CVE-2020-3951

The vulnerability allows attackers with non-administrative access to a guest VM with virtual printing enabled to disrupt the Thinprint service, leading to a denial-of-service condition on the affected system.

Technical Details of CVE-2020-3951

This section provides more technical insights into the CVE.

Vulnerability Description

The vulnerability in VMware Workstation and Horizon Client for Windows stems from a heap-overflow issue in Cortado Thinprint.

Affected Systems and Versions

VMware Workstation versions 15.x before 15.5.2
Horizon Client for Windows versions 5.x and prior before 5.4.0

Exploitation Mechanism

Attackers can exploit this vulnerability by gaining non-administrative access to a guest VM with virtual printing enabled, allowing them to trigger a denial-of-service condition on the system.

Mitigation and Prevention

Protecting systems from CVE-2020-3951 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply the necessary patches provided by VMware promptly.
Disable virtual printing if not essential for operations.
Monitor system logs for any suspicious activities.

Long-Term Security Practices

Regularly update VMware Workstation and Horizon Client to the latest versions.
Implement network segmentation to limit the impact of potential attacks.
Conduct security training for users to recognize and report suspicious activities.

Patching and Updates

Ensure that VMware Workstation is updated to version 15.5.2 or later, and Horizon Client for Windows is updated to version 5.4.0 or higher to mitigate the vulnerability.