CVE-2025-48003 is a vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) that involves a protection mechanism failure within the BitLocker encryption feature. BitLocker is designed to provide full disk encryption to protect data confidentiality and integrity on Windows devices. The vulnerability is classified under CWE-693, which refers to protection mechanism failures where security controls do not function as intended. Specifically, this flaw allows an unauthorized attacker to bypass BitLocker's security protections through a physical attack vector. This means that an attacker with physical access to the device can circumvent the encryption safeguards, potentially gaining access to sensitive data without needing authentication or user interaction. The CVSS v3.1 base score for this vulnerability is 6.8 (medium severity), with the vector indicating that the attack requires physical access (AV:P), has low attack complexity (AC:L), requires no privileges (PR:N), no user interaction (UI:N), and impacts confidentiality, integrity, and availability to a high degree (C:H/I:H/A:H). The scope remains unchanged (S:U), and there is no known exploit in the wild at the time of publication. No patches or mitigations have been linked yet, indicating that this is a newly disclosed issue. The vulnerability highlights a critical weakness in BitLocker's protection mechanism that undermines the trust in full disk encryption on affected Windows 10 systems, especially in environments where physical device security cannot be guaranteed.

For European organizations, this vulnerability poses a significant risk to data confidentiality and integrity, especially for entities relying on BitLocker for endpoint encryption on Windows 10 Version 1809 devices. Organizations in sectors such as finance, healthcare, government, and critical infrastructure that handle sensitive personal or proprietary data could face data breaches if attackers gain physical access to devices. The ability to bypass encryption without authentication means that stolen or lost devices are at heightened risk of data compromise. This could lead to violations of the EU General Data Protection Regulation (GDPR), resulting in regulatory penalties and reputational damage. Additionally, the impact extends to operational availability if attackers manipulate or corrupt data after bypassing protections. The medium CVSS score reflects that while exploitation requires physical access, the consequences of successful exploitation are severe. Given that Windows 10 Version 1809 is an older release, some organizations may still be using it due to legacy application dependencies, increasing their exposure. The lack of known exploits in the wild suggests limited immediate threat but does not preclude future exploitation attempts, especially by sophisticated adversaries targeting high-value European assets.

European organizations should prioritize upgrading affected systems to a more recent and supported version of Windows 10 or Windows 11 where this vulnerability is presumably addressed. Until upgrades can be completed, organizations should enforce strict physical security controls to prevent unauthorized access to devices, including secure storage, access logging, and surveillance in sensitive areas. Implementing hardware-based security modules such as TPM (Trusted Platform Module) with secure boot can add layers of defense. Organizations should also consider deploying additional encryption solutions or multi-factor authentication for device access to complement BitLocker. Regular audits of device inventory and encryption status are essential to identify and remediate vulnerable endpoints. Endpoint detection and response (EDR) tools can help detect suspicious physical tampering attempts. Finally, organizations should monitor Microsoft advisories for patches or updates related to CVE-2025-48003 and apply them promptly once available.