CVE-2025-53718 is a use-after-free vulnerability classified under CWE-416 found in the Windows Ancillary Function Driver for WinSock component of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability arises from improper handling of memory, where the driver attempts to use memory after it has been freed, leading to undefined behavior that an attacker can leverage. An authorized local attacker with low privileges can exploit this flaw to escalate their privileges to higher levels, potentially SYSTEM level, by manipulating the vulnerable driver. The attack complexity is high, requiring specific conditions and knowledge of the system internals, but it does not require user interaction. The vulnerability affects confidentiality, integrity, and availability, as an attacker gaining elevated privileges can access sensitive data, modify system configurations, or disrupt system operations. Although no exploits are currently known in the wild, the vulnerability is publicly disclosed and thus may attract attackers. No patches have been linked yet, but Microsoft is expected to release updates. The CVSS v3.1 base score is 7.0, with vector AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H, indicating local attack vector, high attack complexity, low privileges required, no user interaction, unchanged scope, and high impact on confidentiality, integrity, and availability.

For European organizations, this vulnerability poses a significant risk, especially for those still operating Windows 10 Version 1809, which is an older but still in-use OS version in many enterprises. Successful exploitation could allow attackers to escalate privileges locally, potentially leading to full system compromise. This can result in unauthorized access to sensitive data, disruption of critical services, and the ability to deploy further malware or ransomware. Sectors such as finance, healthcare, government, and critical infrastructure are particularly vulnerable due to the sensitive nature of their data and operations. The requirement for local access limits remote exploitation but insider threats or attackers gaining initial footholds via other means could leverage this vulnerability to deepen their control. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate it, as public disclosure often leads to exploit development. The absence of patches increases exposure, especially in environments with delayed update cycles.

1. Restrict local access to systems running Windows 10 Version 1809, ensuring only trusted users have physical or remote desktop access. 2. Implement strict privilege management and monitoring to detect unusual privilege escalation attempts. 3. Apply any forthcoming Microsoft security updates promptly once released to address this vulnerability. 4. Utilize endpoint detection and response (EDR) solutions to monitor for suspicious activity related to WinSock or driver manipulation. 5. Consider upgrading affected systems to a more recent, supported version of Windows 10 or Windows 11 to reduce exposure to legacy vulnerabilities. 6. Conduct regular security audits and vulnerability assessments focusing on legacy systems. 7. Employ application whitelisting and restrict execution of unauthorized code to limit exploitation avenues. 8. Educate IT staff and users about the risks of local privilege escalation and insider threats to improve detection and response.