CVE-2025-24054 is a vulnerability classified under CWE-73 (External Control of File Name or Path) affecting Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The issue arises from improper handling of file names or paths within the NTLM authentication mechanism, which is used for network authentication in Windows environments. An attacker without any privileges can exploit this vulnerability remotely over the network by manipulating file paths involved in the NTLM process, leading to spoofing attacks. Spoofing here refers to the attacker impersonating a legitimate entity to gain unauthorized access or intercept communications. The vulnerability impacts confidentiality by potentially allowing attackers to redirect or intercept authentication requests or data, but it does not affect the integrity or availability of the system. Exploitation requires user interaction, such as the victim initiating a connection or authentication process. No public exploits have been reported yet, and Microsoft has not provided a patch at the time of publication, though the vulnerability is officially recognized and tracked. The CVSS v3.1 base score is 6.5, indicating a medium severity level, with attack vector being network, low attack complexity, no privileges required, user interaction required, and impact limited to confidentiality. This vulnerability is particularly relevant for organizations still running Windows 10 Version 1809, which is an older release and may lack recent security updates. The NTLM protocol itself is known for legacy compatibility but has been discouraged in favor of more secure authentication methods. This vulnerability underscores the risks of relying on outdated OS versions and legacy authentication protocols.

For European organizations, the primary impact of CVE-2025-24054 is the potential compromise of confidentiality in network authentication processes. Attackers could spoof legitimate authentication requests, potentially gaining unauthorized access to network resources or intercepting sensitive information. This could lead to further lateral movement within networks or data leakage. Organizations relying on Windows 10 Version 1809, especially those with legacy systems or insufficient patching policies, are at higher risk. Critical sectors such as finance, healthcare, government, and industrial control systems could face increased exposure due to the sensitive nature of their data and the reliance on Windows-based infrastructure. The lack of impact on integrity and availability reduces the risk of system disruption or data tampering but does not eliminate the threat of unauthorized data exposure. The requirement for user interaction limits the attack surface somewhat but does not negate the risk, as social engineering or phishing could facilitate exploitation. The absence of known exploits in the wild provides a window for proactive mitigation before active attacks emerge.

To mitigate CVE-2025-24054, European organizations should prioritize upgrading from Windows 10 Version 1809 to a supported and patched Windows version, as this older release is no longer receiving security updates. Where upgrading is not immediately feasible, organizations should consider disabling NTLM authentication entirely or restricting its use via Group Policy to reduce exposure to NTLM-based attacks. Implementing network-level protections such as SMB signing, enforcing SMB encryption, and deploying intrusion detection systems capable of identifying NTLM spoofing attempts can help detect and block exploitation attempts. User awareness training to reduce the likelihood of social engineering or phishing that could trigger user interaction is also critical. Network segmentation and least privilege principles should be enforced to limit the impact of any successful spoofing. Regular auditing of authentication logs and monitoring for unusual NTLM activity can provide early warning signs. Finally, organizations should stay alert for official patches or advisories from Microsoft and apply them promptly once available.