CVE-2025-24985 is an integer overflow or wraparound vulnerability identified in the Windows Fast FAT Driver component of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The flaw arises due to improper handling of integer values within the FAT driver, which can lead to an overflow condition. This overflow can be exploited by an unauthorized attacker with local access and requiring user interaction to execute arbitrary code on the affected system. The vulnerability impacts the confidentiality, integrity, and availability of the system, as it allows code execution at a high privilege level. The CVSS v3.1 base score is 7.8, reflecting high severity with an attack vector of local access (AV:L), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The scope is unchanged (S:U), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). The exploitability is functional (E:F), remediation level is official (RL:O), and the report confidence is confirmed (RC:C). No public exploits are known at this time, but the vulnerability poses a significant risk to systems still running this legacy Windows version, especially in environments where local user access cannot be tightly controlled. The vulnerability is categorized under CWE-190 (Integer Overflow or Wraparound).

For European organizations, the impact of CVE-2025-24985 can be substantial, particularly for those still operating legacy Windows 10 Version 1809 systems. Successful exploitation could lead to full system compromise, allowing attackers to execute arbitrary code, potentially leading to data breaches, ransomware deployment, or disruption of critical services. The requirement for local access and user interaction limits remote exploitation but does not eliminate risk in environments with shared or multi-user systems, such as corporate desktops, kiosks, or public terminals. Sectors like manufacturing, healthcare, and government agencies that often have legacy systems are especially vulnerable. The high impact on confidentiality, integrity, and availability means that sensitive data could be exposed or altered, and system availability could be disrupted, affecting business continuity and regulatory compliance under GDPR and other European data protection laws.

To mitigate CVE-2025-24985, European organizations should prioritize upgrading affected systems from Windows 10 Version 1809 to a supported and patched version of Windows 10 or Windows 11, as Microsoft has not yet released a patch for this specific build. Until upgrades can be completed, organizations should implement strict local access controls to limit user interaction with vulnerable systems, including disabling or restricting access to removable media and FAT file system operations where feasible. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor for anomalous behavior indicative of exploitation attempts. Regularly audit and remove legacy systems from critical network segments and ensure that user education programs emphasize the risks of executing untrusted code or interacting with unknown media. Additionally, maintain robust backup and recovery procedures to minimize impact in case of compromise.