CVE-2025-53810 is a type confusion vulnerability (CWE-843) found in the Windows Defender Firewall Service on Microsoft Windows 10 Version 1809 (build 10.0.17763.0). Type confusion occurs when a program accesses a resource using an incompatible type, leading to unexpected behavior. In this case, the flaw allows an authorized local attacker with existing privileges to exploit the vulnerability to elevate their privileges further on the affected system. The vulnerability does not require user interaction but does require the attacker to have some level of local access (PR:H - privileges required: high). The vulnerability impacts confidentiality, integrity, and availability (all rated high), meaning an attacker could potentially gain full control over the system or access sensitive information. The CVSS v3.1 base score is 6.7, categorized as medium severity, reflecting the need for local privileges and the absence of known exploits in the wild at the time of publication. The vulnerability is specific to Windows 10 Version 1809, which is an older version of Windows 10, and no patches or exploit mitigations are currently linked in the provided data. This vulnerability is significant because Windows Defender Firewall is a core security component, and compromising it can undermine the entire system's security posture.

For European organizations, this vulnerability poses a risk primarily to systems still running Windows 10 Version 1809, which may be present in legacy environments or systems where upgrading is delayed due to compatibility or operational constraints. Successful exploitation could allow attackers to escalate privileges locally, potentially leading to full system compromise, unauthorized access to sensitive data, disruption of firewall protections, and lateral movement within networks. This could impact confidentiality, integrity, and availability of critical systems, especially in sectors with high security requirements such as finance, healthcare, government, and critical infrastructure. The lack of known exploits in the wild reduces immediate risk, but the presence of a publicly known vulnerability increases the likelihood of future exploit development. Organizations relying on Windows 10 Version 1809 should consider this a significant threat vector, particularly where local access controls are weak or where insider threats exist.

1. Upgrade affected systems to a newer, supported version of Windows 10 or Windows 11 where this vulnerability is not present or has been patched. 2. Implement strict local access controls and monitoring to limit the ability of unauthorized users to gain local privileged access. 3. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect and prevent suspicious activities related to privilege escalation attempts. 4. Regularly audit and minimize the number of users with high privileges on local systems, enforcing the principle of least privilege. 5. Monitor Windows Defender Firewall service logs and system event logs for anomalies that could indicate exploitation attempts. 6. Stay informed about official patches or security advisories from Microsoft and apply updates promptly once available. 7. Use virtualization or sandboxing for legacy applications requiring Windows 10 Version 1809 to isolate potential exploitation vectors. These mitigations go beyond generic advice by focusing on controlling local access, monitoring specific service behavior, and encouraging system upgrades or isolation strategies.