CVE-2022-31243 : Security Advisory and Response

This article provides details about CVE-2022-31243, a vulnerability related to DMA transactions causing SMRAM corruption through a TOCTOU attack.

Understanding CVE-2022-31243

This section will cover what CVE-2022-31243 is and its impact.

What is CVE-2022-31243?

The CVE-2022-31243 vulnerability is associated with DMA transactions targeted at input buffers used for the software SMI handler in the FvbServicesRuntimeDxe driver, leading to SMRAM corruption.

The Impact of CVE-2022-31243

The vulnerability, discovered by Insyde engineering with insights from Intel's iSTARE group, poses a risk of SMRAM corruption, impacting system security.

Technical Details of CVE-2022-31243

This section will delve into the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability arises from DMA transactions aimed at input buffers used by the FvbServicesRuntimeDxe driver's SMI handler, potentially causing SMRAM corruption.

Affected Systems and Versions

The affected systems include unspecified vendors and products with versions susceptible to SMRAM corruption due to this vulnerability.

Exploitation Mechanism

Exploiting CVE-2022-31243 involves manipulating DMA transactions to target input buffers of the vulnerable SMI handler, leading to SMRAM corruption.

Mitigation and Prevention

This section will outline steps to mitigate the vulnerability and prevent future occurrences.

Immediate Steps to Take

Immediate actions include applying the respective kernel patches released to fix the vulnerability and enhancing system security measures.

Long-Term Security Practices

In the long term, maintain updated software versions, follow secure coding practices, and conduct regular security audits to prevent similar vulnerabilities.

Patching and Updates

Ensure timely installation of Kernel 5.2: 05.27.21, Kernel 5.3: 05.36.21, Kernel 5.4: 05.44.21, and Kernel 5.5: 05.52.21 to address the CVE-2022-31243 vulnerability.