CVE-2025-53141 is a vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) involving a NULL pointer dereference within the Windows Ancillary Function Driver for WinSock. This driver is part of the Windows networking stack responsible for socket operations. The flaw allows an authorized attacker with local access to the system to trigger a NULL pointer dereference, leading to a system crash or, more critically, to elevate their privileges to SYSTEM level. This elevation of privilege can enable the attacker to execute arbitrary code with high-level permissions, compromising system confidentiality, integrity, and availability. The vulnerability requires local access and low complexity to exploit, with no user interaction needed, making it a significant threat in environments where multiple users share systems or where attackers can gain initial footholds with limited privileges. Although no known exploits are currently reported in the wild, the absence of patches increases the risk of future exploitation. The vulnerability is classified under CWE-476 (NULL Pointer Dereference), which typically leads to denial of service or escalation scenarios. The CVSS v3.1 base score of 7.8 reflects high impact on confidentiality, integrity, and availability, with attack vector local, attack complexity low, privileges required low, and no user interaction necessary. This vulnerability affects legacy Windows 10 systems, which remain in use in many enterprise environments due to application compatibility or upgrade delays.

For European organizations, the impact of CVE-2025-53141 can be substantial, particularly in sectors relying on legacy Windows 10 Version 1809 systems such as manufacturing, healthcare, and government agencies. Successful exploitation allows attackers to gain SYSTEM-level privileges, potentially leading to full system compromise, data breaches, disruption of critical services, and lateral movement within networks. Confidentiality is at risk as attackers can access sensitive data; integrity is compromised through unauthorized code execution or system modifications; availability can be affected by system crashes caused by the NULL pointer dereference. The local attack vector means that insider threats or attackers who have gained limited access can escalate privileges, increasing the threat surface. The lack of available patches at the time of disclosure means organizations must rely on compensating controls to mitigate risk. The vulnerability could also facilitate ransomware deployment or espionage activities targeting European critical infrastructure and enterprises.

1. Restrict local access to systems running Windows 10 Version 1809 by enforcing strict access controls and limiting user privileges to the minimum necessary. 2. Implement application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious activities indicative of privilege escalation attempts. 3. Employ network segmentation to isolate legacy systems and reduce the risk of lateral movement if an attacker gains initial access. 4. Monitor system logs and security events for signs of exploitation attempts related to WinSock or unexpected system crashes. 5. Prepare for rapid deployment of official patches or updates from Microsoft once released; prioritize patching of critical systems. 6. Consider upgrading affected systems to supported Windows versions where feasible to eliminate exposure to this legacy vulnerability. 7. Conduct user awareness and insider threat training to reduce risk from authorized users exploiting local access. 8. Use virtualization or sandboxing for legacy applications to contain potential exploitation impact.