CVE-2025-24991 is a medium-severity vulnerability classified as CWE-125 (Out-of-bounds Read) affecting the NTFS file system driver in Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The flaw arises when the NTFS driver improperly handles certain file system operations, allowing an authorized local attacker to read memory outside the intended buffer boundaries. This out-of-bounds read can lead to unauthorized disclosure of sensitive information residing in adjacent memory regions. Exploitation requires local access and user interaction but does not require elevated privileges, which lowers the barrier somewhat but still limits remote exploitation. The vulnerability does not impact system integrity or availability, focusing solely on confidentiality. The CVSS 3.1 vector (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N) reflects these characteristics, with a base score of 5.5. No public exploits or active exploitation campaigns have been reported as of the publication date. The vulnerability was reserved in late January 2025 and published in March 2025. No patches were linked at the time of reporting, indicating that organizations should monitor for forthcoming updates from Microsoft. The vulnerability is significant for environments where sensitive data confidentiality is critical and where Windows 10 Version 1809 remains in use, despite being an older release. Attackers with local access could leverage this flaw to extract information that might aid further attacks or data leakage.

For European organizations, the primary impact is the potential unauthorized disclosure of sensitive information due to the out-of-bounds read in NTFS. This could include exposure of confidential files or memory contents that may contain credentials, encryption keys, or proprietary data. Since the vulnerability requires local access and user interaction, the risk is higher in environments with shared or multi-user systems, or where attackers can trick users into executing malicious actions. Sectors such as finance, healthcare, government, and critical infrastructure are particularly sensitive to confidentiality breaches. The lack of impact on integrity and availability reduces the risk of system disruption but does not diminish the importance of protecting sensitive data. Organizations still running Windows 10 Version 1809, which is an older version, face increased risk due to potentially reduced security support and patch availability. The vulnerability could be leveraged as part of a multi-stage attack chain, making it a valuable target for attackers aiming to escalate privileges or move laterally within networks.

1. Upgrade to a supported and fully patched version of Windows 10 or later, as Windows 10 Version 1809 is outdated and may no longer receive security updates. 2. Apply any security patches released by Microsoft addressing CVE-2025-24991 immediately upon availability. 3. Restrict local access to systems running Windows 10 Version 1809 by enforcing strict access controls and limiting user permissions to the minimum necessary. 4. Educate users to avoid executing untrusted files or actions that could trigger the vulnerability, reducing the likelihood of user interaction exploitation. 5. Implement endpoint detection and response (EDR) solutions to monitor for unusual local activity indicative of exploitation attempts. 6. Regularly audit and inventory systems to identify those still running vulnerable versions and prioritize their remediation. 7. Use application whitelisting and least privilege principles to minimize the attack surface. 8. In high-security environments, consider isolating legacy systems or using virtualization to contain potential exploitation.