CVE-2025-24985 is an integer overflow vulnerability classified under CWE-190, found in the Windows Fast FAT Driver component of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The flaw arises when the driver improperly handles integer values during FAT file system operations, leading to an overflow or wraparound condition. This can corrupt memory or allow an attacker to manipulate program flow. The vulnerability enables an unauthorized attacker with local access to execute arbitrary code on the affected system, potentially escalating privileges or installing persistent malware. The CVSS 3.1 vector (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C) indicates that the attack requires local access and user interaction but no privileges, with low attack complexity. The impact on confidentiality, integrity, and availability is high, as successful exploitation can lead to full system compromise. Although no public exploits are known yet, the vulnerability is publicly disclosed and considered critical for legacy systems. The lack of available patches at the time of disclosure necessitates urgent attention from affected users. The vulnerability is particularly relevant for environments where Windows 10 Version 1809 remains in use, often due to legacy application dependencies or delayed upgrade cycles.

For European organizations, the impact of CVE-2025-24985 is significant, especially for those still operating Windows 10 Version 1809 in production environments. Successful exploitation can lead to local code execution, enabling attackers to bypass security controls, escalate privileges, and potentially deploy ransomware or other malware. This threatens the confidentiality of sensitive data, integrity of systems, and availability of critical services. Sectors such as finance, healthcare, manufacturing, and government, which often have legacy systems, are particularly vulnerable. The requirement for local access and user interaction somewhat limits remote exploitation but does not eliminate risk, especially in environments with many users or shared workstations. The absence of known exploits currently provides a window for proactive mitigation, but the public disclosure increases the risk of future exploit development. European organizations must prioritize identifying and remediating affected systems to prevent potential breaches and operational disruptions.

1. Upgrade affected systems from Windows 10 Version 1809 to a supported and patched Windows version to eliminate the vulnerability. 2. If immediate upgrade is not feasible, implement strict local access controls to limit user permissions and reduce the risk of exploitation. 3. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious activities related to FAT file system operations. 4. Educate users about the risks of interacting with untrusted media or files that could trigger the vulnerability. 5. Regularly audit and inventory systems to identify those running the vulnerable Windows version. 6. Monitor security advisories from Microsoft for any forthcoming patches or mitigations specific to this CVE. 7. Use network segmentation to isolate legacy systems and reduce the attack surface. 8. Implement strict USB and removable media policies to prevent introduction of malicious files exploiting the FAT driver. 9. Maintain up-to-date backups to enable recovery in case of compromise. 10. Conduct penetration testing and vulnerability assessments focusing on local privilege escalation vectors to detect exploitation attempts.