On September 9, 2025, Microsoft disclosed two new vulnerabilities in Windows BitLocker, its widely used full-disk encryption technology. Both flaws have been classified as “Important” and pose a serious risk if left unpatched.
Key Details
- CVE-2025-54911 & CVE-2025-54912 – Both are Use-After-Free vulnerabilities, a memory corruption issue where freed memory is incorrectly reused.
- Impact – An attacker with local access could escalate privileges to the SYSTEM level, effectively taking full control of the affected device.
- Capabilities with SYSTEM privileges – Installing malicious software, modifying or deleting data, and creating new user accounts with elevated rights.
- Exploitation likelihood – Microsoft currently rates exploitation as “less likely,” and no active attacks have been reported.
Why This Matters
BitLocker is designed to protect sensitive data at rest, especially in enterprise and government environments. But these flaws highlight a key risk: if an attacker gains initial access, they could potentially bypass critical security boundaries.
In today’s landscape, even “less likely” vulnerabilities deserve attention—because sophisticated adversaries are increasingly chaining bugs together to achieve privilege escalation.
What Security Teams Should Do
Stay vigilant – Monitor for abnormal privilege escalation attempts in your environment.
Patch immediately – Ensure all systems are updated with the latest September 2025 security patches.
Audit privileged access – Limit who can log in locally and enforce least-privilege principles.
Layer defences – BitLocker is strong, but it cannot compensate for weak endpoint hygiene or unpatched systems.
