CVE-2020-4031 Explained : Impact and Mitigation

CVE-2020-4031, assigned by GitHub_M, pertains to a use-after-free vulnerability in gdi_SelectObject in FreeRDP.

Understanding CVE-2020-4031

What is CVE-2020-4031?

In FreeRDP before version 2.1.2, a use-after-free vulnerability exists in gdi_SelectObject, impacting all FreeRDP clients using compatibility mode with /relax-order-checks.

The Impact of CVE-2020-4031

This vulnerability allows attackers to execute arbitrary code or cause a denial of service (DoS) condition on affected systems.

Technical Details of CVE-2020-4031

Vulnerability Description

The use-after-free vulnerability in gdi_SelectObject in FreeRDP before version 2.1.2 allows for potential code execution or DoS attacks.

Affected Systems and Versions

Vendor: FreeRDP
Product: FreeRDP
Versions Affected: < 2.1.2

Exploitation Mechanism

Attackers can exploit this vulnerability by manipulating memory allocation, leading to the execution of malicious code or system crashes.

Mitigation and Prevention

Immediate Steps to Take

Update FreeRDP to version 2.1.2 or later to mitigate the vulnerability.
Disable compatibility mode with /relax-order-checks if not required.

Long-Term Security Practices

Regularly update software and apply security patches promptly.
Implement network segmentation and access controls to limit the impact of potential attacks.
Conduct regular security assessments and audits to identify and address vulnerabilities.

Patching and Updates

Ensure that all systems running FreeRDP are updated to version 2.1.2 or above to address the use-after-free vulnerability.