CVE-2025-54911 is a high-severity use-after-free vulnerability identified in Microsoft Windows 10 Version 1809, specifically affecting the BitLocker component. Use-after-free (CWE-416) vulnerabilities occur when a program continues to use a pointer after the memory it points to has been freed, potentially leading to arbitrary code execution or privilege escalation. In this case, the flaw allows an authorized local attacker to elevate their privileges by exploiting improper memory management within BitLocker. BitLocker is a full disk encryption feature integrated into Windows, responsible for protecting data by encrypting entire volumes. The vulnerability requires local access with some privileges (low privileges) and user interaction, as indicated by the CVSS vector (AV:L/AC:L/PR:L/UI:R). The attacker can leverage this flaw to gain higher privileges, potentially SYSTEM-level, thereby compromising confidentiality, integrity, and availability of the system. The CVSS score of 7.3 reflects a high severity due to the combination of high impact on confidentiality, integrity, and availability, and relatively low complexity of exploitation. No known exploits are currently reported in the wild, and no patches have been linked yet, indicating that this vulnerability is newly disclosed and may be targeted in the future. The affected version is Windows 10 Version 1809 (build 10.0.17763.0), which is an older release but still in use in some environments. The vulnerability's exploitation requires local access and user interaction, which somewhat limits remote exploitation but still poses a significant risk in environments where users have access to vulnerable systems. Attackers could use this vulnerability to bypass security controls, install persistent malware, or access sensitive data protected by BitLocker encryption.

For European organizations, the impact of CVE-2025-54911 can be significant, especially in sectors relying on Windows 10 Version 1809 systems with BitLocker enabled for data protection. Successful exploitation can lead to privilege escalation, allowing attackers to execute code with elevated rights, disable security features, or extract sensitive encrypted data. This can result in data breaches, loss of intellectual property, disruption of business operations, and compliance violations under regulations such as GDPR. Organizations with legacy systems or delayed patch management processes are particularly vulnerable. The requirement for local access and user interaction means insider threats or attackers with physical or remote desktop access pose the greatest risk. In environments where BitLocker is used to protect sensitive data, this vulnerability undermines the trust in encryption safeguards, potentially exposing confidential information. Additionally, the high impact on confidentiality, integrity, and availability could facilitate ransomware attacks or persistent footholds within networks. European organizations in critical infrastructure, finance, healthcare, and government sectors are especially at risk due to the sensitive nature of their data and regulatory scrutiny.

1. Immediate mitigation should include identifying and inventorying all Windows 10 Version 1809 systems with BitLocker enabled. 2. Restrict local user privileges to the minimum necessary to reduce the attack surface, enforcing the principle of least privilege. 3. Implement strict access controls and monitoring for local user activities, especially on systems handling sensitive data. 4. Educate users about the risks of interacting with untrusted content or executing unknown applications to reduce the likelihood of user interaction exploitation. 5. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect and block suspicious activities related to privilege escalation attempts. 6. Since no patch is currently linked, monitor Microsoft security advisories closely for updates or hotfixes addressing this vulnerability and apply them promptly once available. 7. Consider upgrading affected systems to a more recent, supported Windows version where this vulnerability is not present or has been patched. 8. Use network segmentation to limit the spread of potential compromises originating from vulnerable endpoints. 9. Conduct regular security audits and penetration testing focusing on privilege escalation vectors to identify and remediate similar weaknesses.