CVE-2025-53137 is a use-after-free vulnerability classified under CWE-416 found in the Windows Ancillary Function Driver for WinSock on Microsoft Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability arises when the driver improperly manages memory, freeing an object while it is still in use, which can lead to arbitrary code execution or privilege escalation. An attacker with authorized local access and low privileges can exploit this flaw to elevate their privileges to SYSTEM level without requiring user interaction. The vulnerability has a CVSS 3.1 base score of 7.0, indicating high severity, with attack vector local (AV:L), attack complexity high (AC:H), privileges required low (PR:L), no user interaction (UI:N), and impacts on confidentiality, integrity, and availability all rated high (C:H/I:H/A:H). Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk due to the potential for complete system compromise. The flaw specifically affects Windows 10 Version 1809, an older but still deployed operating system version, particularly in enterprise and industrial environments. The lack of an official patch at the time of publication increases the urgency for mitigation through access controls and monitoring. This vulnerability highlights the risks associated with legacy Windows versions and the importance of timely patch management and system upgrades.

For European organizations, the impact of CVE-2025-53137 is substantial. Successful exploitation allows an attacker with local access to escalate privileges to SYSTEM level, potentially leading to full control over affected systems. This can result in unauthorized access to sensitive data, disruption of critical services, and the ability to deploy further malware or ransomware. Organizations in sectors such as finance, healthcare, manufacturing, and government, which often rely on legacy Windows 10 1809 systems, face increased risk of operational disruption and data breaches. The vulnerability compromises confidentiality, integrity, and availability simultaneously, making it a critical concern for maintaining compliance with data protection regulations like GDPR. Additionally, the high attack complexity and requirement for local access limit remote exploitation but do not eliminate insider threats or attacks leveraging initial footholds. The absence of known exploits in the wild currently reduces immediate risk but does not preclude future exploitation, especially as threat actors develop proof-of-concept code.

To mitigate CVE-2025-53137, European organizations should prioritize the following actions: 1) Apply official security patches from Microsoft as soon as they become available; 2) For environments where patching is delayed, restrict local access to systems running Windows 10 Version 1809 by enforcing strict access controls and network segmentation; 3) Employ endpoint detection and response (EDR) solutions to monitor for unusual privilege escalation attempts and anomalous behavior related to WinSock driver usage; 4) Conduct regular audits of user privileges and remove unnecessary local administrative rights; 5) Encourage migration to supported and updated Windows versions to reduce exposure to legacy vulnerabilities; 6) Implement application whitelisting to prevent unauthorized code execution; 7) Educate IT staff and users about the risks of local privilege escalation vulnerabilities and the importance of reporting suspicious activity promptly. These targeted measures go beyond generic advice by focusing on access control, monitoring, and legacy system management specific to this vulnerability.