CVE-2022-33986 Explained : Impact and Mitigation

This article provides an in-depth analysis of CVE-2022-33986, a vulnerability related to DMA attacks on the parameter buffer used by the VariableRuntimeDxe software SMI handler.

Understanding CVE-2022-33986

In this section, we will explore what CVE-2022-33986 is and its impact.

What is CVE-2022-33986?

CVE-2022-33986 involves DMA attacks on the parameter buffer used by the VariableRuntimeDxe software SMI handler, leading to a TOCTOU attack that could corrupt SMRAM.

The Impact of CVE-2022-33986

The vulnerability could result in a TOCTOU attack on the SMI handler, potentially causing corruption of SMRAM. It was discovered by Insyde engineering during a security review.

Technical Details of CVE-2022-33986

This section delves into the specific technical aspects of the vulnerability.

Vulnerability Description

DMA attacks targeting the Parameter buffer utilized by the VariableRuntimeDxe software SMI handler may result in a TOCTOU attack, impacting the integrity of SMRAM.

Affected Systems and Versions

The vulnerability affects Kernel 5.4: 05.44.23 and Kernel 5.5: 05.52.23. No specific vendor or product is identified as affected.

Exploitation Mechanism

The exploitation involves manipulating DMA attacks on the parameter buffer to exploit the SMI handler, leading to SMRAM corruption.

Mitigation and Prevention

In this section, we discuss steps to mitigate and prevent CVE-2022-33986.

Immediate Steps to Take

Apply the necessary updates to Kernel versions 5.4 and 5.5 to address the vulnerability.
Monitor system logs for any unusual behavior that might indicate an ongoing attack.

Long-Term Security Practices

Regular security audits and reviews can help identify vulnerabilities before they are exploited.
Implement security best practices to minimize the risk of DMA attacks and TOCTOU vulnerabilities.

Patching and Updates

Ensure that Kernel 5.4: 05.44.23 and Kernel 5.5: 05.52.23 are updated to the fixed versions to prevent potential exploitation.