CVE-2024-37978 is a high-severity stack-based buffer overflow vulnerability (CWE-121) identified in Microsoft Windows 11 version 22H2 (build 10.0.22621.0). The vulnerability specifically affects the Secure Boot security feature, which is designed to ensure that only trusted software is loaded during the system boot process. A stack-based buffer overflow occurs when more data is written to a buffer located on the stack than it can hold, potentially allowing an attacker to overwrite adjacent memory and execute arbitrary code. In this case, the overflow can be triggered remotely (Attack Vector: Adjacent network, AV:A) without requiring privileges (PR:N), but it does require user interaction (UI:R), such as opening a malicious file or link. The vulnerability impacts confidentiality, integrity, and availability (all rated high), meaning an attacker could bypass Secure Boot protections, execute arbitrary code with system-level privileges, and potentially compromise the entire system's trust chain. The vulnerability has a CVSS v3.1 base score of 8.0, indicating high severity, but no known exploits have been reported in the wild as of the publication date (July 9, 2024). The vulnerability was reserved on June 10, 2024, and is publicly disclosed with enriched information from CISA. No official patches or mitigations have been linked yet, which suggests that organizations should prioritize monitoring and prepare for imminent updates from Microsoft. The Secure Boot bypass could allow attackers to load unsigned or malicious bootloaders or kernel drivers, undermining the platform's root of trust and potentially enabling persistent, stealthy malware infections that survive OS reinstalls or disk formatting.

For European organizations, this vulnerability poses a significant risk, especially for enterprises and government agencies relying on Windows 11 22H2 for endpoint security and system integrity. The Secure Boot feature is a critical security control to prevent boot-level malware and rootkits, which are notoriously difficult to detect and remove. A successful exploitation could lead to full system compromise, data breaches involving sensitive or regulated information (e.g., GDPR-protected data), and disruption of critical services. Industries such as finance, healthcare, energy, and public administration, which often mandate strict security baselines, could face operational disruptions and regulatory penalties if compromised. Additionally, the requirement for user interaction means phishing or social engineering campaigns could be leveraged to trigger the exploit, increasing the attack surface. The absence of known exploits in the wild currently provides a window for proactive defense, but the high severity and potential impact necessitate urgent attention. The vulnerability also threatens the supply chain security of software and hardware relying on Windows 11 Secure Boot, potentially affecting trust in digital certificates and signed software within European markets.

1. Immediate deployment of any forthcoming security patches from Microsoft is critical; organizations should monitor Microsoft Security Update Guides and Windows Update channels closely. 2. Until patches are available, enforce strict application whitelisting and endpoint detection and response (EDR) solutions to detect anomalous behavior indicative of exploitation attempts. 3. Educate users about the risks of phishing and social engineering attacks that could trigger the vulnerability, emphasizing caution with unsolicited files or links. 4. Implement network segmentation and restrict access to systems running Windows 11 22H2 to limit exposure to adjacent network attacks. 5. Utilize hardware-based security features such as TPM (Trusted Platform Module) and ensure Secure Boot is enabled and properly configured to reduce attack vectors. 6. Conduct regular security audits and vulnerability assessments focusing on boot integrity and firmware security. 7. Prepare incident response plans specifically addressing boot-level compromises to enable rapid containment and recovery. 8. Consider temporary use of alternative OS versions or configurations if critical systems cannot be patched immediately, balancing operational needs and security.