CVE-2024-28924 is a stack-based buffer overflow vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability pertains to a Secure Boot security feature bypass, which is critical in ensuring the integrity of the boot process by preventing unauthorized or malicious code from executing before the operating system loads. The flaw arises due to improper handling of input data, leading to a stack buffer overflow condition. Exploiting this vulnerability could allow an attacker with high privileges (PR:H) and local access (AV:L) to execute arbitrary code with elevated privileges, potentially compromising system confidentiality, integrity, and availability. The vulnerability does not require user interaction (UI:N), and the scope is unchanged (S:U), meaning the impact is limited to the vulnerable component without affecting other system components directly. The CVSS v3.1 base score is 6.7, categorized as medium severity, reflecting the balance between the high impact on confidentiality, integrity, and availability and the requirement for high privileges and local access. No known exploits are currently reported in the wild, and no patches have been linked yet, indicating that mitigation may rely on vendor updates or workarounds once available. The vulnerability is classified under CWE-121, which is a common weakness related to stack-based buffer overflows, a well-known and critical class of memory corruption bugs that can lead to arbitrary code execution or system crashes. Given the nature of Secure Boot, exploitation could undermine the trusted boot process, potentially allowing persistent malware or rootkits to evade detection and maintain control over the system at a low level.

For European organizations, especially those relying on Windows 10 Version 1809 in critical infrastructure, government, finance, and industrial control systems, this vulnerability poses a significant risk. The ability to bypass Secure Boot can lead to persistent, stealthy malware infections that are difficult to detect and remove, threatening the integrity of sensitive data and system operations. Organizations with legacy systems still running this older Windows version are particularly vulnerable, as these systems may not receive regular security updates. The requirement for local high-privilege access limits remote exploitation but does not eliminate insider threats or scenarios where attackers gain initial footholds through other means. The compromise of Secure Boot undermines hardware-rooted trust, potentially allowing attackers to install bootkits or firmware-level malware, which can survive OS reinstalls and evade traditional endpoint protections. This could lead to data breaches, operational disruptions, and long-term compromise of critical assets. The medium severity rating suggests that while the vulnerability is serious, the exploitation complexity and access requirements reduce the likelihood of widespread immediate impact. However, targeted attacks against high-value European organizations remain a concern, especially in sectors with strategic importance or sensitive data.

Given the absence of an official patch at the time of this report, European organizations should implement the following specific mitigations: 1) Restrict and monitor administrative and local privileged access strictly to minimize the risk of exploitation by insiders or lateral movement. 2) Employ application whitelisting and endpoint detection and response (EDR) solutions capable of detecting anomalous behavior indicative of buffer overflow exploitation or Secure Boot tampering. 3) Enforce strict Secure Boot policies and verify Secure Boot configurations regularly using tools such as Windows Defender System Guard or third-party integrity checkers to detect unauthorized changes. 4) Plan and prioritize upgrading or migrating systems from Windows 10 Version 1809 to supported, fully patched Windows versions to eliminate exposure. 5) Implement network segmentation to isolate legacy systems and limit the spread of potential compromises. 6) Conduct regular security audits and penetration testing focused on privilege escalation and boot process integrity. 7) Maintain robust incident response plans that include firmware and boot-level compromise scenarios. These measures go beyond generic advice by focusing on access control, system integrity verification, and proactive system lifecycle management tailored to the specifics of this vulnerability.