CVE-2025-53147 is a use-after-free vulnerability classified under CWE-416 affecting the Windows Ancillary Function Driver for WinSock component in Microsoft Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability arises when the driver improperly handles memory, freeing an object while it is still in use, which can lead to arbitrary code execution or privilege escalation. An authorized attacker with local access and low privileges can exploit this flaw to elevate their privileges to higher levels, potentially SYSTEM level, thereby gaining full control over the affected system. The vulnerability does not require user interaction but has a high attack complexity, meaning exploitation requires specific conditions or expertise. The CVSS v3.1 base score is 7.0, reflecting high impact on confidentiality, integrity, and availability, but limited by the need for local access and complex exploitation. No public exploits or patches are currently available, but the vulnerability is publicly disclosed and should be considered critical for affected systems. The flaw specifically targets the WinSock ancillary driver, a core networking component, which could allow attackers to manipulate network-related processes or escalate privileges through crafted local operations. This vulnerability is particularly relevant for organizations still running Windows 10 Version 1809, which is an older release with reduced support, increasing the risk of exploitation due to delayed patching.

For European organizations, this vulnerability poses a significant risk, especially for those maintaining legacy Windows 10 Version 1809 systems in production environments. Successful exploitation could lead to full system compromise, allowing attackers to access sensitive data, disrupt operations, or move laterally within networks. Critical sectors such as finance, healthcare, government, and industrial control systems could face severe confidentiality breaches and operational disruptions. Since the vulnerability requires local access, insider threats or attackers who gain initial footholds via phishing or physical access could leverage this flaw to escalate privileges and deepen their control. The lack of available patches increases exposure time, and organizations with strict regulatory compliance (e.g., GDPR) may face legal and reputational consequences if breaches occur. Additionally, the use-after-free nature of the vulnerability could lead to system instability or denial of service, impacting availability of critical services.

Organizations should prioritize upgrading or patching Windows 10 Version 1809 systems as soon as Microsoft releases a security update addressing CVE-2025-53147. Until patches are available, restrict local access to sensitive systems by enforcing strict access controls and monitoring local user activities for unusual privilege escalation attempts. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect exploitation attempts targeting the WinSock driver. Disable or limit unnecessary local accounts and services that could be leveraged for local attacks. Conduct regular audits of system versions and ensure legacy systems are identified and either upgraded or isolated from critical network segments. Implement network segmentation to reduce the risk of lateral movement if an attacker exploits this vulnerability. Educate IT staff and users about the risks of local privilege escalation and enforce strong physical security controls to prevent unauthorized local access.