A cybersecurity researcher, known as Chaotic Eclipse, has released a proof-of-concept exploit for a Windows privilege escalation zero-day vulnerability called "MiniPlasma," which allows attackers to gain SYSTEM privileges on fully patched Windows systems. The vulnerability affects the cldflt.sys Cloud Filter driver and was reported by Google Project Zero in September 2020, assigned the identifier CVE-2020-17103, and claimed to be resolved by Microsoft in December 2020. However, Chaotic Eclipse asserts that the vulnerability remains unpatched. Testing confirmed that the exploit works on Windows 11 Pro, enabling command prompt access with SYSTEM privileges from a standard user account. Will Dormann, a vulnerability analyst, verified the exploit's effectiveness but noted it did not work in the latest Windows 11 Insider Preview Canary build. The exploit leverages the undocumented CfAbortHydration API to manage registry key creation improperly. Chaotic Eclipse has previously disclosed other Windows zero-day vulnerabilities and claims their actions are a protest against Microsoft's handling of vulnerabilities.