CVE-2025-24061 is a vulnerability classified under CWE-693 (Protection Mechanism Failure) affecting Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The flaw resides in the Mark of the Web (MOTW) security feature, which is designed to mark files downloaded from the internet with a security zone identifier to enforce restrictions when opening these files. Due to improper enforcement or bypass of these protections, an unauthorized local attacker can circumvent the MOTW restrictions, potentially executing malicious code or accessing sensitive data that should be sandboxed or blocked. The vulnerability requires local access and user interaction, meaning an attacker must have some foothold on the system and trick a user into opening a malicious file or link. The CVSS 3.1 score of 7.8 reflects high impact on confidentiality, integrity, and availability, with low attack complexity and no privileges required. Although no exploits are currently known in the wild, the vulnerability poses a significant risk due to the widespread use of Windows 10 Version 1809 in enterprise environments. The lack of available patches at the time of publication increases the urgency for organizations to implement interim mitigations. The failure in the protection mechanism could lead to local privilege escalation, unauthorized data access, or execution of arbitrary code, undermining system security and user trust.

For European organizations, the impact of CVE-2025-24061 is substantial, particularly for those still operating Windows 10 Version 1809 in production environments. The vulnerability can lead to unauthorized local privilege escalation, allowing attackers to gain higher-level access than intended, potentially compromising sensitive data and critical systems. This is especially concerning for sectors such as finance, healthcare, government, and critical infrastructure, where data confidentiality and system integrity are paramount. The bypass of MOTW protections could facilitate the execution of malicious payloads that evade standard security controls, increasing the risk of ransomware, data breaches, or persistent threats. Additionally, the requirement for user interaction means phishing or social engineering campaigns could be leveraged to exploit this vulnerability. The absence of patches at the time of disclosure means organizations must rely on mitigations and heightened monitoring, increasing operational overhead and risk exposure. Legacy systems and those with delayed update cycles in European enterprises are particularly vulnerable, potentially leading to widespread exploitation if attackers develop working exploits.

1. Immediately identify and inventory all systems running Windows 10 Version 1809 within the organization to assess exposure. 2. Restrict local user permissions to the minimum necessary to reduce the risk of local exploitation. 3. Disable or restrict the use of Mark of the Web (MOTW) where feasible, such as through Group Policy or registry settings, to limit the impact of the bypass. 4. Implement strict application whitelisting and endpoint protection solutions capable of detecting anomalous behavior related to file execution and privilege escalation. 5. Educate users on the risks of opening files or links from untrusted sources to reduce the likelihood of successful user interaction exploitation. 6. Monitor system logs and security alerts for unusual activity indicative of exploitation attempts. 7. Prepare to deploy security patches immediately upon release from Microsoft and test them in controlled environments before wide deployment. 8. Consider upgrading affected systems to a more recent, supported Windows version where this vulnerability is not present or has been patched. 9. Employ network segmentation to limit lateral movement if a local compromise occurs. 10. Collaborate with cybersecurity teams to update incident response plans to include scenarios involving local privilege escalation via MOTW bypass.