CVE-2025-27471 is a vulnerability identified in Microsoft Windows 10 Version 1809, specifically affecting the Microsoft Streaming Service component. The issue is classified under CWE-591, which pertains to sensitive data storage in improperly locked memory. This means that sensitive data handled by the streaming service is stored in memory regions that are not adequately protected against unauthorized access. While the vulnerability does not directly compromise confidentiality or integrity, it enables an unauthorized attacker to cause a denial of service (DoS) over a network. The CVSS v3.1 base score is 5.9 (medium severity), reflecting that the attack vector is network-based (AV:N), requires no privileges (PR:N), and no user interaction (UI:N), but has a high attack complexity (AC:H). The impact is limited to availability (A:H), with no confidentiality (C:N) or integrity (I:N) impact. The vulnerability is exploitable remotely without authentication, but the complexity of exploitation is high, possibly due to specific conditions or timing requirements. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was published on April 8, 2025, with the reservation date on February 26, 2025. The lack of patch availability indicates that affected organizations should prioritize monitoring and mitigation to prevent potential exploitation. The vulnerability affects Windows 10 Version 1809 (build 10.0.17763.0), an older version of Windows 10, which may still be in use in some environments. The Microsoft Streaming Service is likely involved in media streaming or related functionalities within the OS, and improper memory locking could lead to service crashes or resource exhaustion, causing denial of service conditions.

For European organizations, the primary impact of CVE-2025-27471 is the potential disruption of services relying on Windows 10 Version 1809 systems running the Microsoft Streaming Service. This could affect enterprises using legacy systems for media streaming, digital signage, or other streaming-dependent applications. The denial of service could lead to operational downtime, affecting business continuity and user experience. Although the vulnerability does not expose sensitive data or allow unauthorized data modification, the availability impact could disrupt critical services, especially in sectors like media, telecommunications, education, and public services that may still operate legacy Windows 10 systems. Additionally, organizations with strict uptime requirements or those providing streaming services to customers could face reputational damage and financial losses due to service interruptions. The medium severity score suggests that while the threat is not critical, it should not be ignored, particularly in environments where Windows 10 Version 1809 remains in use and where the Microsoft Streaming Service is integral to operations.

1. Upgrade and Patch Management: Organizations should prioritize upgrading affected systems from Windows 10 Version 1809 to a more recent, supported version of Windows 10 or Windows 11, where this vulnerability is presumably addressed. If patches become available, apply them promptly. 2. Service Hardening: Disable or restrict the Microsoft Streaming Service on systems where it is not essential to reduce the attack surface. 3. Network Controls: Implement network segmentation and firewall rules to limit exposure of vulnerable systems to untrusted networks, especially blocking unnecessary inbound traffic targeting the streaming service ports. 4. Monitoring and Detection: Deploy monitoring tools to detect unusual service crashes or network activity indicative of attempted exploitation. Log and analyze streaming service failures for early signs of attack. 5. Incident Response Preparedness: Develop and test incident response plans specifically addressing denial of service scenarios affecting streaming services. 6. Legacy System Management: Identify and inventory all systems running Windows 10 Version 1809 and assess the necessity of their continued use. Plan for phased decommissioning or upgrade to reduce risk exposure. 7. User Awareness: Inform IT staff about this vulnerability and ensure they understand the importance of maintaining updated systems and monitoring service health.