CVE-2024-42446 is a high-severity vulnerability identified in AMI's AptioV BIOS firmware, specifically affecting version BKS_5.0. The vulnerability is classified as a Time-of-check Time-of-use (TOCTOU) race condition (CWE-367), which occurs when a system checks a condition and then uses the result of that check at a later time, allowing an attacker to exploit the timing gap between these operations. In this case, the flaw exists within the BIOS layer, a critical component responsible for initializing hardware and bootstrapping the operating system. Exploiting this race condition requires local access with high privileges (as indicated by the CVSS vector AV:L/PR:H), meaning an attacker must already have significant control or access to the system. The vulnerability does not require user interaction and has a scope that affects confidentiality, integrity, and availability, potentially allowing arbitrary code execution at the BIOS level. This could lead to persistent compromise, as malicious code running in BIOS can evade detection by operating system-level security controls and survive OS reinstalls. While no known exploits are currently reported in the wild, the high CVSS score of 7.5 reflects the serious risk posed by this vulnerability if weaponized. The lack of available patches at the time of publication increases the urgency for affected organizations to monitor for updates and implement compensating controls. Given the critical role of BIOS in system security, exploitation could allow attackers to manipulate system boot processes, install rootkits, or bypass security mechanisms, severely undermining system trustworthiness and security posture.

For European organizations, the impact of CVE-2024-42446 could be significant, especially in sectors relying on hardware-level security such as finance, government, critical infrastructure, and manufacturing. Successful exploitation could lead to persistent firmware-level compromise, enabling attackers to maintain long-term access, exfiltrate sensitive data, or disrupt operations. The ability to execute arbitrary code at the BIOS level threatens confidentiality, integrity, and availability of affected systems. This is particularly concerning for organizations with strict regulatory requirements around data protection (e.g., GDPR) and operational continuity. Additionally, the local privilege requirement means insider threats or attackers who have already gained elevated access could leverage this vulnerability to escalate control and evade detection. The lack of known exploits currently provides a window for proactive mitigation, but the potential for future exploitation necessitates urgent attention. BIOS-level compromises are notoriously difficult to detect and remediate, increasing the risk of persistent and stealthy attacks that could impact European organizations' trust in their IT infrastructure.

1. Immediate inventory and identification of systems running AMI AptioV BIOS version BKS_5.0 to assess exposure. 2. Engage with AMI and hardware vendors to obtain and apply BIOS firmware updates or patches as soon as they become available. 3. Implement strict access controls to limit local administrative privileges, reducing the risk of local attackers exploiting the vulnerability. 4. Employ hardware-based security features such as Trusted Platform Module (TPM) and Secure Boot to help detect unauthorized BIOS modifications. 5. Monitor system logs and firmware integrity using specialized endpoint detection tools capable of detecting BIOS-level anomalies. 6. Enforce strong physical security controls to prevent unauthorized local access to critical systems. 7. Develop and test incident response plans that include firmware compromise scenarios to ensure rapid detection and remediation. 8. Consider network segmentation and isolation for critical systems to limit lateral movement if a BIOS-level compromise occurs. 9. Educate IT and security teams about the risks of TOCTOU vulnerabilities and the importance of timely patch management at the firmware level.