CVE-2025-27741 is a high-severity vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0), specifically involving an out-of-bounds read flaw in the Windows NTFS file system driver. This vulnerability is classified under CWE-125, which pertains to out-of-bounds read errors where a program reads data past the boundaries of allocated memory. In this case, the flaw allows an unauthorized local attacker to read memory beyond intended limits, potentially leading to privilege escalation. The vulnerability requires local access with low complexity and no privileges but does require user interaction. Exploiting this flaw could enable an attacker to elevate their privileges on the affected system, gaining higher-level access than initially permitted. The CVSS v3.1 base score is 7.8, reflecting high severity with impacts on confidentiality, integrity, and availability. The vector indicates local attack vector (AV:L), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), unchanged scope (S:U), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). No known exploits are currently reported in the wild, and no patches have been linked yet, though the vulnerability is publicly disclosed and tracked by CISA enrichment. The flaw resides in the NTFS driver, a critical component responsible for file system operations, making exploitation potentially impactful on system stability and security. Given the nature of the vulnerability, successful exploitation could allow attackers to bypass security controls and execute code or perform actions with elevated privileges, compromising system integrity and confidentiality.

For European organizations, this vulnerability poses a significant risk, especially for enterprises and government agencies still operating legacy Windows 10 Version 1809 systems. Privilege escalation vulnerabilities in core OS components like NTFS can lead to full system compromise, unauthorized data access, and disruption of critical services. Organizations in sectors such as finance, healthcare, and public administration, which often handle sensitive personal and financial data, could face data breaches or ransomware attacks leveraging this flaw. The requirement for local access and user interaction somewhat limits remote exploitation but does not eliminate risk from insider threats or social engineering attacks that trick users into executing malicious payloads. The lack of available patches increases exposure time, and the high impact on confidentiality, integrity, and availability means that exploitation could result in severe operational and reputational damage. Additionally, compliance with GDPR and other data protection regulations could be jeopardized if this vulnerability leads to unauthorized data disclosure or system compromise.

European organizations should prioritize upgrading or patching affected Windows 10 Version 1809 systems as soon as official fixes become available from Microsoft. Until patches are released, organizations should implement strict local access controls, including limiting administrative privileges and enforcing least privilege principles to reduce the risk of local exploitation. Employing application whitelisting and endpoint detection and response (EDR) solutions can help detect and block suspicious activities indicative of exploitation attempts. User education is critical to minimize the risk of social engineering that could trigger user interaction required for exploitation. Regularly auditing and monitoring NTFS-related system logs may help identify anomalous behavior. Organizations should also consider migrating to supported Windows versions with active security updates to reduce exposure to legacy vulnerabilities. Network segmentation and strong authentication mechanisms can further limit the impact of a compromised endpoint. Finally, maintaining comprehensive backups and incident response plans will help mitigate damage if exploitation occurs.