CVE-2025-62571 is a vulnerability classified under CWE-20 (Improper Input Validation) affecting the Windows Installer component in Microsoft Windows 10 Version 1809 (build 17763.0). The flaw arises because the Windows Installer does not properly validate input data, which an authorized local attacker can exploit to escalate privileges on the affected system. This means that an attacker who already has limited access to the system can manipulate installer inputs to gain higher-level privileges, potentially allowing them to execute arbitrary code with elevated rights, modify system configurations, or disable security controls. The vulnerability does not require user interaction (UI:N) and has low attack complexity (AC:L), but it does require the attacker to have some level of local privileges (PR:L). The scope is unchanged (S:U), indicating the impact is confined to the vulnerable component and does not extend beyond the local system. The CVSS v3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability (all rated high). No public exploits are known at this time, but the vulnerability is published and should be considered a significant risk, especially in environments where Windows 10 1809 remains in use. The lack of available patches at the time of publication means organizations must rely on compensating controls until updates are released.

For European organizations, this vulnerability poses a significant risk primarily to environments still running Windows 10 Version 1809, which may include legacy systems in industrial, governmental, or enterprise sectors. Successful exploitation could allow attackers to gain elevated privileges locally, potentially leading to full system compromise, data breaches, or disruption of critical services. This is particularly concerning for organizations handling sensitive personal data under GDPR, as unauthorized access could lead to compliance violations and heavy fines. The vulnerability could also be leveraged as a stepping stone for lateral movement within networks, increasing the risk of widespread compromise. Given the high impact on confidentiality, integrity, and availability, organizations in sectors such as finance, healthcare, energy, and public administration are at heightened risk. The absence of known exploits currently reduces immediate threat but does not eliminate the risk of future exploitation, especially by sophisticated threat actors targeting European infrastructure.

1. Prioritize upgrading or patching Windows 10 Version 1809 systems as soon as Microsoft releases an official fix for CVE-2025-62571. 2. Until patches are available, restrict local user privileges to the minimum necessary to reduce the pool of potential attackers with local access. 3. Implement application whitelisting and restrict execution of unauthorized installers or scripts to prevent exploitation attempts. 4. Employ enhanced monitoring and logging of Windows Installer activity to detect anomalous or suspicious behavior indicative of exploitation attempts. 5. Use endpoint detection and response (EDR) solutions capable of identifying privilege escalation techniques. 6. Conduct regular audits of local accounts and remove or disable unnecessary accounts with local access. 7. Educate IT staff and users about the risks of local privilege escalation and the importance of maintaining updated systems. 8. Segment critical systems to limit lateral movement opportunities should an attacker gain elevated privileges on one machine.