CVE-2025-24061 is a high-severity vulnerability affecting Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The flaw is categorized under CWE-693, which relates to protection mechanism failures. Specifically, this vulnerability involves a failure in the Windows Mark of the Web (MOTW) security feature. MOTW is designed to mark files downloaded from the internet with a security zone identifier, which triggers security restrictions when the file is opened, such as disabling certain active content or prompting warnings. The vulnerability allows an unauthorized local attacker to bypass these security restrictions, effectively undermining the protection MOTW provides. The CVSS 3.1 base score is 7.8, indicating a high severity level. The vector string (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) shows that the attack requires local access with low attack complexity, no privileges, and user interaction, but can result in high impact on confidentiality, integrity, and availability. The scope remains unchanged. Although no known exploits are currently reported in the wild, the vulnerability could enable attackers to execute malicious code or elevate privileges by circumventing MOTW protections, potentially leading to system compromise or data breaches. No patches or mitigation links are provided yet, indicating that organizations must be vigilant and prepare for updates. This vulnerability is particularly relevant for environments still running Windows 10 Version 1809, which is an older release but may still be in use in some enterprises due to legacy application dependencies or delayed upgrade cycles.

For European organizations, this vulnerability poses a significant risk, especially in sectors where Windows 10 Version 1809 remains deployed. The ability to bypass MOTW protections locally means that an attacker who gains local access—potentially through phishing, social engineering, or physical access—could execute malicious payloads without triggering expected security warnings or restrictions. This could lead to unauthorized data access, modification, or destruction, impacting confidentiality, integrity, and availability of critical systems. Sensitive industries such as finance, healthcare, government, and critical infrastructure could face increased risk of data breaches or operational disruptions. Additionally, the requirement for user interaction means that targeted phishing campaigns could exploit this vulnerability to compromise endpoints. Given the high impact on all three security pillars and the low complexity of attack, organizations must prioritize mitigation to prevent lateral movement or privilege escalation within their networks.

1. Immediate mitigation should include enforcing strict local access controls and limiting user permissions to reduce the risk of unauthorized local access. 2. Educate users about the risks of opening files from untrusted sources and reinforce phishing awareness to minimize the likelihood of user interaction enabling exploitation. 3. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious activities that may attempt to exploit this vulnerability. 4. Where possible, upgrade affected systems from Windows 10 Version 1809 to a more recent, supported Windows version that includes security improvements and patches. 5. Implement network segmentation to limit the impact of a compromised endpoint. 6. Monitor for unusual local file execution behaviors and audit local user activities to detect potential exploitation attempts. 7. Stay alert for official patches or security advisories from Microsoft and apply updates promptly once available.