CVE-2025-54093 is a vulnerability classified under CWE-367, indicating a time-of-check to time-of-use (TOCTOU) race condition within the TCP/IP implementation of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). This type of race condition occurs when a system checks a condition (time-of-check) and then uses the result of that check later (time-of-use), but the state changes between these two operations, allowing an attacker to exploit the timing gap. In this case, the flaw exists in the TCP/IP stack, a core networking component responsible for managing network communications. An attacker with local, low-level privileges can exploit this race condition to escalate their privileges to higher levels, potentially gaining administrative rights. The vulnerability has a CVSS 3.1 base score of 7.0, reflecting high severity due to its impact on confidentiality, integrity, and availability, despite requiring local access and high attack complexity. No user interaction is needed, and the scope is unchanged, meaning the exploit affects only the vulnerable component without extending beyond the local system. Currently, there are no known exploits in the wild, and no official patches have been released, although Microsoft has acknowledged the issue. The vulnerability is particularly concerning for environments where Windows 10 Version 1809 remains in use, often due to legacy application dependencies or delayed upgrade cycles. The race condition could allow attackers to bypass security controls, access sensitive data, modify system configurations, or disrupt services by leveraging elevated privileges.

For European organizations, the impact of CVE-2025-54093 can be significant, especially in sectors relying on legacy Windows 10 Version 1809 systems. Privilege escalation vulnerabilities enable attackers who have gained limited local access—such as through compromised user accounts, insider threats, or physical access—to obtain administrative privileges. This can lead to full system compromise, data breaches, unauthorized changes to system configurations, and disruption of critical services. Organizations in finance, healthcare, government, and critical infrastructure are particularly at risk due to the sensitivity of their data and the importance of system availability. The vulnerability's exploitation could facilitate lateral movement within networks, undermining network segmentation and defense-in-depth strategies. Given the high impact on confidentiality, integrity, and availability, successful exploitation could result in severe operational and reputational damage, regulatory penalties under GDPR, and financial losses. The lack of patches increases the urgency for mitigation, especially in environments where upgrading the operating system is not immediately feasible.

1. Restrict local access strictly to trusted users and devices to reduce the risk of exploitation by unauthorized or low-privileged users. 2. Monitor and audit local user activities and privilege escalations to detect suspicious behavior early. 3. Apply any forthcoming security patches from Microsoft promptly once available; maintain close communication with Microsoft security advisories. 4. Consider upgrading affected systems from Windows 10 Version 1809 to a supported and patched Windows version to eliminate exposure to this vulnerability. 5. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect and block exploitation attempts. 6. Harden network configurations to limit unnecessary local access and isolate critical systems. 7. Use virtualization or containerization to isolate legacy applications requiring Windows 10 Version 1809, minimizing the attack surface. 8. Implement strict privilege management policies, including least privilege principles and just-in-time access, to limit the impact of any privilege escalation. 9. Conduct regular vulnerability assessments and penetration testing focused on local privilege escalation vectors.