CVE-2024-37973 is a vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) that involves uncontrolled recursion, categorized under CWE-674. This flaw affects the Secure Boot security feature, which is designed to ensure that only trusted software is loaded during the system startup process. The uncontrolled recursion can be triggered remotely without authentication or user interaction, leading to a security feature bypass. The vulnerability has a CVSS 3.1 base score of 8.8, indicating high severity, with attack vector being adjacent network (AV:A), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction (UI:N). The impact covers confidentiality, integrity, and availability, all rated high. The flaw allows an attacker to bypass Secure Boot protections, potentially enabling the execution of unauthorized code during boot or compromising system integrity. Although no public exploits have been reported yet, the vulnerability's nature and severity make it a critical concern for affected systems. The vulnerability was reserved in June 2024 and published in July 2024, with no patches currently listed, indicating that mitigation options may be limited until official updates are released. The vulnerability's exploitation could lead to persistent compromise at a low system level, undermining trust in the device's boot process and security assurances.

For European organizations, the impact of CVE-2024-37973 is substantial due to the widespread use of Windows 10 Version 1809 in enterprise environments, especially in sectors with stringent security requirements such as finance, healthcare, and critical infrastructure. The Secure Boot bypass can allow attackers to load malicious bootloaders or kernel-level malware, leading to persistent and stealthy compromises that are difficult to detect and remediate. This can result in data breaches, system outages, and loss of trust in IT systems. The vulnerability's remote exploitability without authentication increases the attack surface, particularly in networked environments where adjacent network access is possible, such as corporate LANs or VPNs. European organizations with legacy systems still running Windows 10 1809 are at heightened risk, as upgrading to newer versions may not be immediate due to operational constraints. The potential for high-impact attacks targeting confidentiality, integrity, and availability makes this vulnerability a critical concern for maintaining compliance with European data protection regulations and cybersecurity directives.

Given the absence of an official patch at the time of this analysis, European organizations should implement the following specific mitigations: 1) Conduct comprehensive asset inventories to identify all systems running Windows 10 Version 1809, prioritizing those with Secure Boot enabled. 2) Restrict network access to vulnerable systems by segmenting networks and applying strict firewall rules to limit adjacent network exposure. 3) Employ network intrusion detection and prevention systems (IDS/IPS) tuned to detect anomalous traffic patterns that could indicate exploitation attempts targeting Secure Boot processes. 4) Where feasible, accelerate migration plans to supported Windows versions with updated security patches and improved Secure Boot implementations. 5) Implement strict boot configuration policies and monitor Secure Boot logs for irregularities that may indicate exploitation attempts. 6) Educate IT staff on the vulnerability specifics to enhance incident response readiness. 7) Engage with Microsoft support channels to obtain early access to patches or workarounds as they become available. These targeted actions go beyond generic advice by focusing on network-level controls, system inventory accuracy, and proactive monitoring tailored to the vulnerability's characteristics.