Zero-Day | Breaking Cybersecurity News | The Hacker News

Chaotic Eclipse, the security researcher behind the recently disclosed Windows flaws, YellowKey and GreenPlasma , has released a proof-of-concept (PoC) for a Windows privilege escalation zero-day flaw that grants attackers SYSTEM privileges on fully patched Windows systems. Codenamed MiniPlasma , the vulnerability impacts "cldflt.sys," which refers to the Windows Cloud Files Mini Filter Driver, and resides in a routine named "HsmOsBlockPlaceholderAccess." It was originally reported to Microsoft by Google Project Zero researcher James Forshaw in September 2020. Although it was assumed that the shortcoming was fixed by Microsoft in December 2020 as part of CVE-2020-17103 , Chaotic Eclipse said further investigation has uncovered that the "exact same issue [...] is actually still present, unpatched." "I'm unsure if Microsoft just never patched the issue or the patch was silently rolled back at some point for unknown reasons. The original PoC by...

An anonymous cybersecurity researcher who disclosed three Microsoft Defender vulnerabilities has returned with two more zero-days involving a BitLocker bypass and a privilege escalation impacting Windows Collaborative Translation Framework (CTFMON). The security defects have been codenamed YellowKey and GreenPlasma , respectively, by the researcher, who goes by the online aliases Chaotic Eclipse and Nightmare-Eclipse. The researcher described YellowKey as "one of the most insane discoveries I ever found," likening the BitLocker bypass to functioning as a backdoor, as the bug is present only in the Windows Recovery Environment ( WinRE ), a built-in framework designed to troubleshoot and repair common unbootable operating system issues. YellowKey affects Windows 11 and Windows Server 2022/2025. At a high level, it involves copying specially crafted "FsTx" files on a USB drive or the EFI partition, plugging the USB drive into the target Windows computer with Bit...