‘GreatXML’ Zero-Day Exploit Bypasses BitLocker

The PoC exploits Microsoft Defender’s offline scan to spawn a SYSTEM shell when rebooting in Recovery Mode. The post ‘GreatXML’ Zero-Day Exploit Bypasses BitLocker appeared first on SecurityWeek .

The reported 'GreatXML' zero-day exploit abuses Microsoft Defender's offline scan process in Windows Recovery Mode to obtain a SYSTEM shell, bypassing BitLocker protections on the underlying volume; this is similar in impact and attack path to other recent BitLocker bypass zero-days that rely on Recovery Environment behavior and physical access.[1][6] This is a traditional OS/platform security vulnerability rather than an AI/ML-specific issue, but it illustrates systemic supply-chain risk in relying on built-in security tooling (e.g., Defender, WinRE) as trusted components without hardening or independent controls. From a CyberSE.AI perspective, organizations should treat native security components in their Windows stack as third‑party dependencies within their broader digital supply chain, ensuring they are inventoried, monitored, and rapidly patched or mitigated when exploit techniques are published. For AI systems running on affected endpoints or servers, controls such as strict physical access policies, restricted recovery-boot paths, hardened boot configurations, and rapid application of Microsoft mitigations reduce the chance that an attacker could use such OS‑level exploits