CVE-2025-54112 is a use-after-free vulnerability (CWE-416) identified in the Microsoft Virtual Hard Drive (VHD) component of Windows 10 Version 1809 (build 17763.0). This vulnerability arises from improper handling of memory allocation and deallocation within the VHD driver or related components, leading to a scenario where freed memory is accessed again. An authorized attacker with local access and low privileges can exploit this flaw to execute arbitrary code in kernel mode, thereby elevating their privileges to SYSTEM level. The vulnerability does not require user interaction but has a high attack complexity due to the need for precise manipulation of the VHD subsystem. Exploitation could allow attackers to bypass security controls, install persistent malware, or disrupt system operations. Although no public exploits have been reported yet, the vulnerability is classified as high severity with a CVSS 3.1 base score of 7.0, reflecting its significant impact on confidentiality, integrity, and availability. The lack of a patch at the time of publication increases the urgency for defensive measures. This vulnerability specifically affects Windows 10 Version 1809, a version that, while superseded by newer releases, remains in use in some enterprise environments due to legacy application dependencies or delayed upgrade cycles.

For European organizations, the impact of CVE-2025-54112 can be substantial, particularly for those still operating Windows 10 Version 1809 in production environments. Successful exploitation enables local attackers to gain SYSTEM-level privileges, potentially leading to full control over affected systems. This can result in unauthorized access to sensitive data, disruption of critical services, and the deployment of persistent malware or ransomware. Sectors such as finance, healthcare, government, and critical infrastructure are especially vulnerable due to the high value of their data and the potential for operational disruption. The vulnerability undermines the confidentiality, integrity, and availability of systems, which could lead to regulatory non-compliance under GDPR and other data protection laws. Additionally, organizations with remote or shared workstation environments may face increased risk if local access controls are weak. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits over time.

1. Apply official Microsoft patches immediately once they become available for Windows 10 Version 1809 to remediate the vulnerability. 2. Until patches are deployed, restrict local access to systems running the affected Windows version by enforcing strict physical and logical access controls. 3. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious activities related to the Virtual Hard Drive subsystem. 4. Conduct thorough audits of user privileges and remove unnecessary local administrator rights to minimize the pool of potential attackers. 5. Implement network segmentation to isolate legacy systems and reduce lateral movement opportunities. 6. Monitor system logs and security alerts for unusual behavior indicative of exploitation attempts, particularly those involving virtual disk operations. 7. Plan and accelerate migration away from Windows 10 Version 1809 to supported and patched Windows versions to reduce exposure to legacy vulnerabilities. 8. Educate IT staff and users about the risks of local privilege escalation vulnerabilities and the importance of timely patching and access controls.