CVE-2022-32954 : Exploit Details and Defense Strategies

An issue was discovered in Insyde InsydeH2O with kernel 5.1 through 5.5. DMA attacks on the SdMmcDevice buffer used by SMM and non-SMM code could cause TOCTOU race-condition issues that could lead to corruption of SMRAM and escalation of privileges. Learn more about this CVE and how to mitigate the risks.

Understanding CVE-2022-32954

Insyde InsydeH2O with kernel 5.1 through 5.5 is vulnerable to DMA attacks that could result in corruption of SMRAM and privilege escalation.

What is CVE-2022-32954?

CVE-2022-32954 is an issue in Insyde InsydeH2O where DMA attacks on the SdMmcDevice buffer may lead to TOCTOU race-condition problems, potentially allowing attackers to corrupt SMRAM and escalate their privileges.

The Impact of CVE-2022-32954

The vulnerability could be exploited to trigger TOCTOU race conditions and corrupt SMRAM, possibly leading to privilege escalation.

Technical Details of CVE-2022-32954

The technical details of the vulnerability include:

Vulnerability Description

DMA attacks on the SdMmcDevice buffer used by SMM and non-SMM code could cause TOCTOU race-condition issues leading to SMRAM corruption and privilege escalation.

Affected Systems and Versions

Insyde InsydeH2O with kernel versions 5.1 through 5.5 are affected by this vulnerability.

Exploitation Mechanism

Attackers could exploit this vulnerability through DMA attacks on the SdMmcDevice buffer, potentially leading to escalation of privileges.

Mitigation and Prevention

To mitigate the risks associated with CVE-2022-32954, consider the following steps:

Immediate Steps to Take

Use IOMMU protection for the ACPI runtime memory used for the command buffer.
Copy the link data to SMRAM before checking it and verify that all pointers are within the buffer.

Long-Term Security Practices

Regularly update the system with security patches and firmware updates.

Patching and Updates

Stay informed about security advisories from Insyde and apply relevant patches and updates promptly.