CVE-2021-42113 : Security Advisory and Response

An SMM callout vulnerability in Insyde InsydeH2O with certain Kernel versions could allow an attacker to hijack code execution in System Management Mode.

Understanding CVE-2021-42113

What is CVE-2021-42113?

An issue in StorageSecurityCommandDxe in Insyde InsydeH2O with specific Kernel versions allows privilege escalation to SMM by manipulating the execution flow of code in System Management Mode.

The Impact of CVE-2021-42113

Exploiting this vulnerability could lead to unauthorized privileges in the System Management Mode, posing a significant security risk to the affected systems.

Technical Details of CVE-2021-42113

Vulnerability Description

The StorageSecurityCommandDxe in Insyde InsydeH2O with Kernel versions 5.1 before 05.14.28, 5.2 before 05.24.28, and 5.3 before 05.32.25 is vulnerable to an SMM callout issue, enabling attackers to control code execution in System Management Mode.

Affected Systems and Versions

Insyde InsydeH2O with Kernel 5.1 before 05.14.28
Insyde InsydeH2O with Kernel 5.2 before 05.24.28
Insyde InsydeH2O with Kernel 5.3 before 05.32.25

Exploitation Mechanism

The vulnerability allows attackers to manipulate the execution flow of code running in System Management Mode, facilitating the privilege escalation attack.

Mitigation and Prevention

Immediate Steps to Take

Apply security patches provided by Insyde or system vendors promptly.
Implement strict access controls and monitoring mechanisms to detect unauthorized SMM activities.

Long-Term Security Practices

Regularly update and patch firmware to mitigate known vulnerabilities.
Conduct security assessments to identify and address system weaknesses proactively.

Patching and Updates

Stay informed about security updates from Insyde and Kernel vendors to apply patches promptly.