CVE-2025-32709 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 occurs due to improper handling of memory, where the system attempts to use memory after it has been freed, leading to undefined behavior. An authorized local attacker can exploit this flaw to elevate privileges on the affected system without requiring user interaction. The attack vector is local (AV:L), meaning the attacker must have some level of access to the system already (PR:L). The vulnerability impacts confidentiality, integrity, and availability (all rated high), as it can allow execution of arbitrary code with elevated privileges, potentially leading to full system compromise. The vulnerability has a CVSS v3.1 base score of 7.8, indicating high severity. No public exploits or patches are currently available, but the vulnerability has been officially published and recognized by CISA. The flaw specifically affects Windows 10 Version 1809, a legacy operating system version that may still be in use in some environments. The lack of user interaction (UI:N) facilitates exploitation once local access is obtained. The vulnerability is critical for environments where local user accounts have limited privileges but could be leveraged to gain administrative control.

For European organizations, this vulnerability poses a significant risk especially to those still operating legacy Windows 10 Version 1809 systems, which may be common in industrial, governmental, or specialized enterprise environments. Successful exploitation can lead to privilege escalation, allowing attackers to bypass security controls, access sensitive data, modify system configurations, or deploy malware with elevated rights. This could result in data breaches, disruption of critical services, or lateral movement within networks. The impact is particularly severe in sectors such as finance, healthcare, energy, and government, where confidentiality and system integrity are paramount. Given the local attack vector, insider threats or compromised user accounts could be leveraged to exploit this vulnerability. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as attackers often develop exploits post-disclosure. Organizations relying on legacy systems without active patching or upgrade plans are at heightened risk.

1. Prioritize upgrading affected systems from Windows 10 Version 1809 to a supported and patched Windows version to eliminate exposure. 2. Apply any security updates or patches released by Microsoft as soon as they become available for this vulnerability. 3. Restrict local user access rights to the minimum necessary, employing the principle of least privilege to reduce the risk of privilege escalation. 4. Implement robust endpoint detection and response (EDR) solutions to monitor for suspicious activities indicative of exploitation attempts, such as unusual process behavior or memory anomalies. 5. Enforce strict access controls and multi-factor authentication (MFA) for local accounts to mitigate risks from compromised credentials. 6. Conduct regular audits of systems running legacy OS versions and develop a decommissioning plan to phase out unsupported software. 7. Educate IT staff and users about the risks associated with legacy systems and the importance of reporting unusual system behavior promptly. 8. Utilize application whitelisting and sandboxing where feasible to limit the impact of potential exploitation.