CVE-2025-54112 is a use-after-free vulnerability identified in the Microsoft Virtual Hard Drive (VHD) component of Windows 10 Version 1809 (build 10.0.17763.0). Use-after-free (CWE-416) vulnerabilities occur when a program continues to use a pointer after the memory it points to has been freed, potentially leading to arbitrary code execution or privilege escalation. In this case, an authorized attacker with local access and low privileges can exploit this flaw to elevate their privileges on the affected system. The vulnerability arises from improper memory management within the VHD driver, which handles virtual hard disk operations. Exploiting this vulnerability requires local access and elevated attack complexity, as indicated by the CVSS vector (AV:L/AC:H/PR:L/UI:N). No user interaction is needed, and the scope remains unchanged, meaning the exploit affects only the vulnerable component without extending beyond the current security context. The CVSS v3.1 base score is 7.0, reflecting high severity due to the potential for complete compromise of confidentiality, integrity, and availability. Although no public exploits have been reported yet, the vulnerability poses a significant risk, especially in environments where Windows 10 Version 1809 is still in use. The absence of a patch link suggests that remediation may not yet be available, underscoring the importance of interim mitigations. This vulnerability is particularly relevant for organizations relying on legacy Windows 10 systems, as attackers with local access could leverage it to gain administrative control, bypassing security controls and potentially deploying further malicious payloads or disrupting operations.

For European organizations, the impact of CVE-2025-54112 can be substantial, especially in sectors where legacy Windows 10 Version 1809 systems remain operational, such as manufacturing, healthcare, and government agencies. Successful exploitation enables attackers to escalate privileges locally, potentially gaining administrative rights and full control over affected systems. This can lead to unauthorized access to sensitive data, system manipulation, deployment of ransomware or other malware, and disruption of critical services. The vulnerability compromises confidentiality, integrity, and availability, increasing the risk of data breaches and operational downtime. Given that many European organizations have complex IT environments with legacy dependencies, the threat is amplified. Additionally, the lack of known exploits in the wild currently provides a window for proactive defense, but the high severity score indicates that once exploited, the consequences could be severe. The vulnerability also poses risks to compliance with European data protection regulations such as GDPR, as privilege escalation could facilitate unauthorized data access or exfiltration.

To mitigate CVE-2025-54112, European organizations should prioritize the following actions: 1) Monitor Microsoft security advisories closely and apply official patches immediately upon release to remediate the vulnerability. 2) Restrict local access to systems running Windows 10 Version 1809 by enforcing strict access controls, limiting administrative privileges, and using network segmentation to reduce attack surface. 3) Employ application whitelisting and endpoint detection and response (EDR) solutions to detect and block suspicious activities indicative of exploitation attempts. 4) Utilize memory protection technologies such as Control Flow Guard (CFG) and Data Execution Prevention (DEP) to hinder exploitation of use-after-free vulnerabilities. 5) Conduct regular audits of legacy systems and plan for upgrades or migrations to supported Windows versions to reduce exposure to unpatched vulnerabilities. 6) Implement robust logging and monitoring to detect anomalous privilege escalation behaviors promptly. 7) Educate IT staff about the risks associated with legacy systems and the importance of timely patch management. These targeted measures go beyond generic advice by focusing on access control, legacy system management, and proactive detection tailored to the vulnerability's characteristics.