CVE-2024-28896 is a heap-based buffer overflow vulnerability (CWE-122) affecting Microsoft Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability relates to a security feature bypass in the Secure Boot mechanism, which is designed to ensure that only trusted software is loaded during the system startup process. A heap-based buffer overflow occurs when a program writes more data to a buffer located on the heap than it is allocated to hold, potentially allowing an attacker to overwrite adjacent memory. In this case, the overflow could be exploited to bypass Secure Boot protections, undermining the integrity of the boot process and potentially allowing unauthorized code execution with elevated privileges. The vulnerability has a CVSS v3.1 base score of 7.5 (high severity), with the vector indicating that the attack requires adjacent network access (Attack Vector: Adjacent), high attack complexity, no privileges required, no user interaction, and impacts confidentiality, integrity, and availability at a high level. The scope remains unchanged, meaning the impact is confined to the vulnerable component. No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability was reserved in March 2024 and published in April 2024. The lack of user interaction and privileges required, combined with the potential to bypass Secure Boot, makes this a significant threat to system security, particularly for environments relying on Windows 10 Version 1809 for critical operations.

For European organizations, this vulnerability poses a serious risk to the security and trustworthiness of their IT infrastructure. Secure Boot is a foundational security feature used to prevent unauthorized firmware, operating systems, or bootloaders from running at startup. Bypassing this mechanism could allow attackers to implant persistent malware or rootkits that survive reboots and evade detection by traditional security tools. This could lead to full system compromise, data breaches, and disruption of critical services. Organizations in sectors such as finance, healthcare, government, and critical infrastructure, which often rely on Windows 10 systems and require strong endpoint security, are particularly at risk. The high impact on confidentiality, integrity, and availability means sensitive data could be exfiltrated or manipulated, and systems could be rendered inoperable. Given that Windows 10 Version 1809 is an older release, some organizations may still be running it due to legacy application dependencies, increasing their exposure. The absence of known exploits in the wild currently provides a window for mitigation, but the high severity score and potential for privilege escalation make timely remediation essential.

1. Immediate upgrade or patching: Although no official patch links are provided, organizations should monitor Microsoft’s security advisories closely and apply any forthcoming updates promptly. 2. Upgrade to a supported Windows version: Windows 10 Version 1809 is out of mainstream support; migrating to a newer, supported Windows version with active security updates will reduce exposure. 3. Harden Secure Boot configurations: Verify Secure Boot settings in UEFI firmware to ensure they are enabled and properly configured, minimizing the attack surface. 4. Network segmentation: Since the attack vector is adjacent network access, segmenting networks to limit exposure to untrusted devices can reduce risk. 5. Endpoint detection and response (EDR): Deploy advanced EDR solutions capable of detecting anomalous behaviors indicative of boot-level compromise or memory corruption. 6. Restrict physical and network access: Limit access to systems running vulnerable versions to trusted personnel and networks only. 7. Conduct regular integrity checks: Use tools to verify bootloader and firmware integrity to detect unauthorized modifications early. 8. Incident response readiness: Prepare for potential exploitation scenarios by having forensic and recovery procedures in place.