CVE-2025-54112 is a high-severity use-after-free vulnerability identified in the Microsoft Virtual Hard Drive (VHD) component of Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability arises from improper handling of memory in the VHD driver, leading to a use-after-free condition. Specifically, after a memory object is freed, the system continues to use the dangling pointer, which can cause memory corruption. An authorized local attacker with limited privileges can exploit this flaw to elevate their privileges on the affected system. The vulnerability does not require user interaction but does require local access with some privileges (PR:L). The attack complexity is high (AC:H), meaning exploitation requires specific conditions or expertise. The vulnerability impacts confidentiality, integrity, and availability, as successful exploitation can lead to full system compromise. No known exploits are currently in the wild, and no patches have been linked yet, indicating that mitigation relies on system hardening and monitoring until official updates are released.

For European organizations, this vulnerability poses a significant risk, especially for enterprises and government agencies still running Windows 10 Version 1809, which is an older but still in-use OS version in some sectors. Exploitation could allow attackers to escalate privileges from a low-privileged user account to SYSTEM-level access, enabling them to install malware, exfiltrate sensitive data, or disrupt services. This is particularly critical for organizations handling sensitive personal data under GDPR, as a breach could lead to regulatory penalties and reputational damage. Additionally, the use-after-free nature of the vulnerability could be leveraged to bypass security controls and evade detection, complicating incident response efforts. The lack of available patches increases the window of exposure, making proactive mitigation essential.

1. Immediate mitigation should include restricting local access to trusted users only, minimizing the number of accounts with local login rights. 2. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor for suspicious activities indicative of privilege escalation attempts. 3. Disable or restrict the use of the Virtual Hard Drive feature if it is not required for business operations, reducing the attack surface. 4. Apply strict group policy settings to limit the execution of unauthorized code and enforce least privilege principles. 5. Monitor system logs for anomalous behavior related to memory management or VHD operations. 6. Plan and prioritize upgrading affected systems to a supported and patched Windows version, as Windows 10 Version 1809 is nearing or past end-of-support status. 7. Once patches become available from Microsoft, deploy them promptly following testing in controlled environments.