CVE-2025-53154 is a vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) involving a NULL pointer dereference in the Windows Ancillary Function Driver for WinSock. This driver component is responsible for network socket operations, and the flaw allows an authorized local attacker to trigger a NULL pointer dereference condition. Exploiting this vulnerability results in a local privilege escalation (LPE), enabling the attacker to gain higher system privileges than initially granted. The vulnerability does not require user interaction and has a low attack complexity, meaning it can be exploited reliably by a user with limited privileges. The CVSS v3.1 base score is 7.8, reflecting high severity with impacts to confidentiality, integrity, and availability (all rated high). The scope is unchanged, meaning the exploit affects only the vulnerable component on the local system. No known exploits are currently in the wild, and no patches have been linked yet, indicating organizations must remain vigilant. This vulnerability is categorized under CWE-476 (NULL Pointer Dereference), which typically leads to system crashes or unexpected behavior that attackers can leverage for privilege escalation. Since the affected version is Windows 10 1809, a legacy OS version still in use in some environments, the risk remains significant for unpatched systems.

For European organizations, this vulnerability poses a significant risk especially to those still operating Windows 10 Version 1809 in production environments. Successful exploitation allows attackers with local access to escalate privileges, potentially leading to full system compromise, unauthorized access to sensitive data, and disruption of critical services. This can impact confidentiality by exposing sensitive information, integrity by allowing unauthorized modifications, and availability by causing system crashes or denial of service. Sectors such as government, finance, healthcare, and critical infrastructure that rely on legacy Windows 10 systems are particularly vulnerable. The lack of public exploits reduces immediate risk but also means attackers may develop exploits in the future. The vulnerability could be leveraged in multi-stage attacks where initial access is gained through other means, then privilege escalation is used to deepen the compromise. Given the high prevalence of Windows 10 in Europe, especially in enterprise environments, the potential impact is broad. Organizations with strict regulatory requirements (e.g., GDPR) face additional compliance risks if breaches occur due to this vulnerability.

European organizations should take immediate steps to mitigate this vulnerability. First, identify and inventory all systems running Windows 10 Version 1809 to assess exposure. Since no official patches are currently linked, organizations should monitor Microsoft security advisories closely for updates and apply patches promptly once available. In the interim, restrict local access to critical systems by enforcing strict user account controls and limiting administrative privileges. Implement application whitelisting and endpoint protection solutions that can detect abnormal behavior related to privilege escalation attempts. Employ network segmentation to isolate legacy systems and reduce attack surface. Regularly audit logs for suspicious local activity indicative of exploitation attempts. Consider upgrading affected systems to a more recent, supported Windows version to eliminate exposure to this and other legacy vulnerabilities. Additionally, educate users about the risks of local privilege escalation and enforce strong authentication and session management policies to reduce the likelihood of unauthorized local access.