Windows 'MiniPlasma' Zero-Day Exploit Grants SYSTEM Access
On May 17, 2026, cybersecurity researcher Chaotic Eclipse released a proof-of-concept exploit named 'MiniPlasma' that enables attackers to gain SYSTEM privileges on fully patched Windows systems. This exploit targets a vulnerability in the 'cldflt.sys' Cloud Filter driver, specifically the 'HsmOsBlockPlaceholderAccess' routine, which was initially reported in 2020 as CVE-2020-17103 and believed to have been patched in December 2020. However, the researcher discovered that the vulnerability remains exploitable, allowing for privilege escalation attacks. The release of this exploit underscores the critical importance of thorough patch validation and continuous security assessments. Organizations must remain vigilant, as previously addressed vulnerabilities can resurface, posing significant security risks. This incident highlights the necessity for robust vulnerability management practices to ensure the effectiveness of security patches.
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