CVE-2025-49762 is a race condition vulnerability categorized under CWE-362, found in the Windows Ancillary Function Driver for WinSock component of Microsoft Windows 10 Version 1507 (build 10240.0). The vulnerability arises from improper synchronization when multiple threads or processes concurrently access shared resources, leading to a race condition. This flaw can be exploited by an attacker with authorized local access and low privileges to elevate their privileges on the system. The attacker leverages the timing window created by the race condition to manipulate the shared resource state, bypassing normal security controls and gaining higher privileges. The vulnerability does not require user interaction but has a high attack complexity, meaning exploitation demands precise timing and conditions. The CVSS 3.1 vector (AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H) indicates local attack vector, high complexity, low privileges required, no user interaction, unchanged scope, and high impact on confidentiality, integrity, and availability. No public exploits are known yet, and no patches have been released at the time of publication. The vulnerability affects legacy Windows 10 systems, which are increasingly rare but may still be in use in some environments. This flaw poses a significant risk as privilege escalation can lead to full system compromise, enabling attackers to install malware, exfiltrate data, or disrupt operations.

For European organizations, the impact of CVE-2025-49762 is significant, especially for those still operating legacy Windows 10 Version 1507 systems. Privilege escalation vulnerabilities allow attackers to gain administrative control, potentially leading to data breaches, ransomware deployment, or disruption of critical services. Sectors such as government, healthcare, finance, and critical infrastructure are particularly vulnerable due to the sensitive nature of their data and operations. The vulnerability could facilitate lateral movement within networks, undermining endpoint security and increasing the risk of widespread compromise. Given the high confidentiality, integrity, and availability impact, exploitation could result in severe operational and reputational damage. Although exploitation complexity is high and no public exploits exist yet, the presence of this vulnerability in unpatched legacy systems poses a persistent threat. Organizations relying on outdated Windows 10 versions without proper segmentation or access controls are at elevated risk.

1. Upgrade affected systems to a supported and patched version of Windows 10 or later, as Windows 10 Version 1507 is outdated and no longer supported by Microsoft. 2. Apply any security updates or patches Microsoft releases addressing this vulnerability as soon as they become available. 3. Restrict local access to systems running legacy Windows 10 versions to trusted personnel only, minimizing the risk of local exploitation. 4. Implement strict access controls and endpoint protection solutions that can detect and block privilege escalation attempts. 5. Employ application whitelisting and behavior monitoring to identify suspicious activities related to WinSock or network driver manipulation. 6. Conduct regular vulnerability assessments and penetration testing focusing on privilege escalation vectors. 7. Educate IT staff and users about the risks of running unsupported operating systems and encourage timely upgrades. 8. Segment networks to limit lateral movement opportunities if a local compromise occurs. 9. Monitor system logs and security alerts for anomalies indicative of race condition exploitation attempts. 10. Develop and test incident response plans specifically addressing privilege escalation scenarios.