CVE-2025-48001 is a time-of-check to time-of-use (TOCTOU) race condition vulnerability identified in Microsoft Windows 10 Version 1809, specifically affecting the BitLocker encryption feature. A TOCTOU race condition occurs when a system checks a condition and then uses the result of that check at a later time, during which the state may have changed, allowing an attacker to exploit the timing window. In this case, the vulnerability allows an unauthorized attacker with physical access to the machine to bypass BitLocker's security protections. BitLocker is designed to protect data by encrypting the entire drive, preventing unauthorized access even if the physical drive is removed. The vulnerability arises because the race condition can be exploited to manipulate the state between the check and use phases, potentially allowing the attacker to access encrypted data without proper authorization. The CVSS v3.1 base score is 6.8, indicating a medium severity level. The attack vector is physical (AV:P), meaning the attacker must have physical access to the device. No privileges or user interaction are required (PR:N, UI:N), and the vulnerability impacts confidentiality, integrity, and availability (C:H, I:H, A:H). There are no known exploits in the wild yet, and no patches have been linked at the time of publication. The vulnerability affects Windows 10 Version 1809 (build 10.0.17763.0), which is an older version of Windows 10. The CWE classification is CWE-367, which relates to TOCTOU race conditions. This vulnerability is significant because BitLocker is widely used in enterprise and governmental environments to secure sensitive data, and a successful exploit could lead to unauthorized data access or manipulation.

For European organizations, this vulnerability poses a considerable risk, especially for sectors that rely heavily on data confidentiality and integrity, such as finance, healthcare, government, and critical infrastructure. Organizations using Windows 10 Version 1809 with BitLocker enabled are at risk of physical data breaches if devices are lost, stolen, or accessed by unauthorized personnel. The ability to bypass BitLocker encryption undermines trust in endpoint security and could lead to data exfiltration, regulatory non-compliance (e.g., GDPR violations), and reputational damage. Since the attack requires physical access, the threat is particularly relevant for organizations with mobile workforces, remote offices, or inadequate physical security controls. Additionally, the vulnerability could be exploited in targeted attacks against high-value assets or personnel. The lack of known exploits in the wild suggests limited immediate risk, but the medium severity and the nature of the vulnerability warrant proactive mitigation to prevent future exploitation.

1. Upgrade to a supported and fully patched version of Windows 10 or later, as Windows 10 Version 1809 is out of mainstream support and may not receive security updates. 2. Implement strict physical security controls to prevent unauthorized access to devices, including secure storage, access logging, and surveillance. 3. Use hardware-based security modules such as TPM (Trusted Platform Module) with BitLocker to enhance protection against physical attacks. 4. Employ multi-factor authentication for device access and consider additional encryption layers or disk protection solutions that are not vulnerable to TOCTOU race conditions. 5. Regularly audit and inventory devices running legacy Windows versions and prioritize their upgrade or replacement. 6. Educate employees on the risks of device theft and the importance of reporting lost or stolen devices promptly. 7. Monitor for unusual device access patterns and implement endpoint detection and response (EDR) tools to detect potential exploitation attempts. 8. If upgrading is not immediately possible, consider disabling BitLocker temporarily or restricting its use on vulnerable systems until a patch or mitigation is available.