CVE-2022-33984 : Exploit Details and Defense Strategies

This article discusses the DMA transaction vulnerability in the SdMmcDevice software SMI handler that could lead to SMRAM corruption through a TOCTOU attack. It was discovered by Insyde engineering and fixed in kernel versions 5.2, 5.3, 5.4, and 5.5.

Understanding CVE-2022-33984

In this section, we will delve into the details of CVE-2022-33984.

What is CVE-2022-33984?

The CVE-2022-33984 vulnerability involves DMA transactions aimed at input buffers used for the SdMmcDevice software SMI handler, resulting in potential SMRAM corruption via a TOCTOU attack.

The Impact of CVE-2022-33984

The vulnerability could be exploited for malicious SMRAM corruption, potentially leading to system compromise and unauthorized access.

Technical Details of CVE-2022-33984

Let's explore the technical aspects of CVE-2022-33984.

Vulnerability Description

The vulnerability arises from DMA transactions targeting input buffers of the SdMmcDevice software SMI handler, enabling attackers to corrupt SMRAM through a TOCTOU attack.

Affected Systems and Versions

The vulnerability affects systems using SdMmcDevice driver with kernel versions 5.2, 5.3, 5.4, and 5.5.

Exploitation Mechanism

Attackers exploit the vulnerability by conducting DMA transactions on specific input buffers, triggering SMRAM corruption.

Mitigation and Prevention

In this section, we will cover steps to mitigate and prevent CVE-2022-33984.

Immediate Steps to Take

System administrators and users should apply the respective kernel patches (5.2: 05.27.25, 5.3: 05.36.25, 5.4: 05.44.25, 5.5: 05.52.25) to safeguard against the vulnerability.

Long-Term Security Practices

Implement robust security practices to prevent DMA attacks and regularly update system components to address emerging vulnerabilities.

Patching and Updates

Stay vigilant for security advisories and promptly apply patches and updates to ensure system resilience against potential threats.