CVE-2025-49675 is a use-after-free vulnerability classified under CWE-416, found in the Kernel Streaming WOW Thunk Service Driver component of Microsoft Windows 10 Version 1507 (build 10.0.10240.0). The vulnerability arises from improper handling of memory, where the driver references memory after it has been freed, leading to undefined behavior. An authorized local attacker can exploit this flaw to elevate their privileges on the affected system, potentially gaining SYSTEM-level access. The attack vector requires local access with low privileges (PR:L) but does not require user interaction (UI:N). The vulnerability affects confidentiality, integrity, and availability (all rated high), indicating that exploitation could lead to complete system compromise, including unauthorized data access, modification, or denial of service. The CVSS v3.1 base score is 7.8, reflecting the high impact and relatively low complexity of exploitation. No patches or official fixes have been published at the time of disclosure, and no known exploits have been observed in the wild. The vulnerability is specific to an older Windows 10 version (1507), which is no longer widely supported, but may still be in use in legacy environments. The Kernel Streaming WOW Thunk Service Driver is a system-level component involved in audio and media streaming, making it a critical part of the OS kernel subsystem. Exploitation could allow attackers to bypass security controls and escalate privileges from a limited user account to full administrative rights.

The primary impact of CVE-2025-49675 is local privilege escalation, enabling attackers with limited access to gain SYSTEM-level privileges. This can lead to full control over the affected system, allowing attackers to install malware, exfiltrate sensitive data, modify system configurations, or disrupt services. The vulnerability compromises confidentiality, integrity, and availability, making it a critical risk for organizations relying on affected Windows 10 versions. Legacy systems running Windows 10 Version 1507 are particularly vulnerable, and if these systems are part of critical infrastructure, industrial control systems, or enterprise environments, the impact could be severe. Additionally, since the vulnerability requires local access, insider threats or attackers who have already gained limited footholds could leverage this flaw to escalate privileges and move laterally within networks. The absence of patches increases the window of exposure, and organizations may face compliance and regulatory risks if vulnerable systems are not remediated promptly.

1. Immediately restrict local user privileges on systems running Windows 10 Version 1507 to the minimum necessary, preventing untrusted users from executing code or accessing sensitive components. 2. Implement strict access controls and monitoring on legacy systems, including enhanced logging and alerting for suspicious activities related to the Kernel Streaming WOW Thunk Service Driver. 3. Isolate legacy Windows 10 Version 1507 machines from critical network segments to reduce the risk of lateral movement. 4. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect and block exploitation attempts targeting this vulnerability. 5. Plan and prioritize upgrading affected systems to supported Windows versions that receive security updates, as Windows 10 Version 1507 is outdated and unsupported. 6. Monitor official Microsoft channels for patches or security advisories related to this CVE and apply updates promptly once available. 7. Conduct internal audits to identify all systems running the vulnerable version and develop a remediation timeline. 8. Educate IT staff and users about the risks of local privilege escalation vulnerabilities and enforce policies to minimize exposure.