CVE-2021-42554 : Exploit Details and Defense Strategies

Insyde InsydeH2O with Kernel versions before 05.08.42 through 05.50.51 has an SMM memory corruption vulnerability. This CVE allows attackers to manipulate SMRAM, potentially leading to privilege escalation to SMM.

Understanding CVE-2021-42554

An issue in Insyde InsydeH2O with specific Kernel versions poses a serious threat due to an SMM memory corruption vulnerability.

What is CVE-2021-42554?

The CVE-2021-42554 vulnerability in Insyde InsydeH2O with Kernel versions before 05.08.42 through 05.50.51 enables potential attackers to tamper with SMRAM, risking escalated privilege access to SMM.

The Impact of CVE-2021-42554

Exploiting this vulnerability could result in unauthorized modification of SMRAM contents, leading to the elevation of privileges to System Management Mode (SMM).

Technical Details of CVE-2021-42554

Insight into the technical aspects of CVE-2021-42554

Vulnerability Description

The vulnerability in FvbServicesRuntimeDxe within Insyde InsydeH2O allows attackers to write predictable data to SMRAM, impacting system security.

Affected Systems and Versions

Kernel versions 5.0 to 5.5 before specific patches.

Exploitation Mechanism

Attackers can exploit this vulnerability to manipulate SMRAM, potentially leading to unauthorized privilege escalation to System Management Mode.

Mitigation and Prevention

Best practices to mitigate and prevent CVE-2021-42554

Immediate Steps to Take

Patch systems with the updated Kernel versions to address the vulnerability.
Monitor system behavior for any unauthorized changes in SMRAM.

Long-Term Security Practices

Regularly update system software to protect against known vulnerabilities.
Implement secure boot mechanisms and system integrity checks.

Patching and Updates

Apply the recommended security patches provided by Insyde and Kernel maintainers to safeguard against CVE-2021-42554.