CVE-2024-37987 is a vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) characterized by a type confusion flaw (CWE-843) that enables an attacker to bypass the Secure Boot security feature. Secure Boot is a critical component of the Windows boot process designed to ensure that only trusted software is loaded during system startup, protecting against boot-level malware and rootkits. The vulnerability arises from improper handling of resource types within the Secure Boot implementation, allowing an attacker to access resources using incompatible types, which can lead to unauthorized code execution or security feature bypass. The CVSS 3.1 base score of 8.0 indicates a high-severity issue with an attack vector of adjacent network (AV:A), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The scope is unchanged (S:U), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). Although no public exploits are known at this time, the vulnerability's nature suggests that exploitation could allow attackers to circumvent Secure Boot protections, potentially leading to persistent and stealthy compromise of affected systems. The vulnerability was reserved on June 10, 2024, and published on July 9, 2024, with no patches currently linked, indicating that mitigation options may be limited until official updates are released.

For European organizations, this vulnerability poses a significant risk, particularly to those relying on Windows 10 Version 1809 in environments where Secure Boot is a critical security control, such as government, finance, healthcare, and critical infrastructure sectors. Exploitation could allow attackers to bypass Secure Boot protections, enabling the execution of unauthorized or malicious code during system startup, which can lead to persistent malware infections, data breaches, and system integrity violations. The high impact on confidentiality, integrity, and availability means that sensitive data could be exposed or altered, and systems could be rendered inoperable. Given the requirement for user interaction, phishing or social engineering campaigns could be used to trigger exploitation. The lack of known exploits currently provides a window for proactive defense, but the presence of a high-severity vulnerability in a widely used OS version necessitates urgent attention. Legacy systems that have not been upgraded or patched are particularly vulnerable, increasing the attack surface within European organizations.

1. Monitor Microsoft security advisories closely and apply official patches or updates as soon as they become available to remediate the vulnerability. 2. For environments where patching is delayed, restrict network access to vulnerable Windows 10 Version 1809 systems, especially from adjacent networks, to reduce exposure. 3. Implement strict user interaction policies and educate users to recognize and avoid phishing or social engineering attempts that could trigger exploitation. 4. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect and block suspicious activities related to Secure Boot bypass attempts. 5. Consider upgrading affected systems to newer, supported Windows versions with improved security features and ongoing patch support. 6. Audit and enforce Secure Boot configurations and firmware integrity checks to detect anomalies. 7. Use network segmentation to isolate critical systems running vulnerable OS versions to limit lateral movement in case of compromise.