CVE-2020-5953 : Security Advisory and Response

A vulnerability exists in System Management Interrupt (SWSMI) handler of InsydeH2O UEFI Firmware code that can lead to code execution in SMM, escalating privilege from ring 0 to ring -2.

Understanding CVE-2020-5953

This CVE involves a vulnerability in the SWSMI handler of InsydeH2O UEFI Firmware code.

What is CVE-2020-5953?

The vulnerability in the SWSMI handler dereferences gRT (EFI_RUNTIME_SERVICES) pointer to call a GetVariable service located outside of SMRAM, allowing code execution in SMM.

The Impact of CVE-2020-5953

The vulnerability can result in escalating privilege from ring 0 to ring -2, potentially leading to unauthorized code execution.

Technical Details of CVE-2020-5953

This section provides more technical insights into the CVE.

Vulnerability Description

The vulnerability lies in the SWSMI handler of InsydeH2O UEFI Firmware code, enabling unauthorized code execution in SMM.

Affected Systems and Versions

Product: n/a
Vendor: n/a
Version: n/a

Exploitation Mechanism

The vulnerability occurs when the SWSMI handler dereferences gRT pointer to call a GetVariable service outside of SMRAM, allowing for code execution in SMM.

Mitigation and Prevention

Protecting systems from CVE-2020-5953 is crucial for maintaining security.

Immediate Steps to Take

Apply security patches provided by the vendor promptly.
Monitor vendor communications for updates and advisories.
Implement strict access controls to limit system exposure.

Long-Term Security Practices

Regularly update firmware and software to patch known vulnerabilities.
Conduct security assessments and audits to identify and address potential weaknesses.

Patching and Updates

Stay informed about security bulletins and patches released by InsydeH2O.
Ensure timely application of firmware updates to mitigate the vulnerability.