CVE-2025-54101 is a use-after-free vulnerability (CWE-416) identified in the Microsoft Windows 10 Version 1809 SMBv3 client component. This vulnerability arises when the SMBv3 client improperly manages memory, leading to a use-after-free condition. An authorized attacker with low privileges and requiring user interaction can exploit this flaw remotely over a network. The exploitation could cause a denial of service (DoS) by crashing the system or potentially executing arbitrary code, although the CVSS vector indicates no confidentiality or integrity impact and only availability impact. The vulnerability requires high attack complexity, low privileges, and user interaction, which limits the ease of exploitation. The CVSS v3.1 base score is 4.8 (medium severity), reflecting these factors. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability affects Windows 10 Version 1809 (build 10.0.17763.0), which is an older version of Windows 10, released in late 2018. SMBv3 is a critical network file sharing protocol widely used in enterprise environments for file and printer sharing, authentication, and inter-process communication. A use-after-free in this component could allow attackers to disrupt availability or potentially escalate attacks if combined with other vulnerabilities. Given the requirement for user interaction and low privileges, exploitation scenarios might involve phishing or social engineering to trigger SMB connections. The lack of confidentiality or integrity impact reduces the risk of data theft or manipulation directly from this vulnerability alone.

For European organizations, this vulnerability poses a moderate risk primarily to availability of systems running Windows 10 Version 1809. Many enterprises and public sector entities in Europe still operate legacy systems due to long upgrade cycles or compatibility requirements, making them susceptible. Disruption of SMB services could impact file sharing, authentication, and network operations, potentially causing downtime or productivity loss. Critical infrastructure sectors relying on SMB for operational technology or internal communications could face operational interruptions. However, the medium severity and requirement for user interaction reduce the likelihood of widespread automated exploitation. Confidentiality and integrity of data are not directly impacted, limiting the risk of data breaches from this vulnerability alone. Organizations with strict patch management policies and those that have migrated to newer Windows versions are less affected. Nonetheless, the presence of this vulnerability in network-facing SMB clients means that targeted attacks against legacy systems remain a concern, especially in sectors with high-value assets or sensitive data.

1. Upgrade affected systems to a supported and updated version of Windows 10 or Windows 11 where this vulnerability is patched or not present. 2. Disable SMBv3 client functionality on systems where it is not required, or restrict SMB traffic using network segmentation and firewall rules to limit exposure. 3. Implement strict user awareness training to reduce the risk of social engineering or phishing that could trigger user interaction required for exploitation. 4. Monitor network traffic for unusual SMB connection attempts or anomalies that could indicate exploitation attempts. 5. Apply principle of least privilege to user accounts to minimize the impact of low-privilege attackers. 6. Use endpoint detection and response (EDR) tools to detect and respond to suspicious activities related to SMB client processes. 7. Regularly review and update incident response plans to include scenarios involving SMB-related vulnerabilities and potential denial of service attacks. 8. Since no patch is currently linked, closely monitor Microsoft security advisories for updates and apply patches promptly once available.