{"id":58004,"date":"2025-01-15T01:33:04","date_gmt":"2025-01-15T01:33:04","guid":{"rendered":"https:\/\/www.threatshub.org\/blog\/microsoft-fixes-under-attack-privilege-escalation-holes-in-hyper-v\/"},"modified":"2025-01-15T01:33:04","modified_gmt":"2025-01-15T01:33:04","slug":"microsoft-fixes-under-attack-privilege-escalation-holes-in-hyper-v","status":"publish","type":"post","link":"https:\/\/www.threatshub.org\/blog\/microsoft-fixes-under-attack-privilege-escalation-holes-in-hyper-v\/","title":{"rendered":"Microsoft fixes under-attack privilege-escalation holes in Hyper-V"},"content":{"rendered":"

Patch Tuesday<\/span> The first Patch Tuesday of 2025 has seen Microsoft address three under-attack privilege-escalation flaws in its Hyper-V hypervisor, plus plenty more problems that deserve your attention.<\/p>\n

The Hyper-V vulnerabilities are CVE-2025-21333<\/a>, CVE-2025-21334<\/a>, and CVE-2025-21335<\/a>, and were already being exploited in the wild as zero-days. They are rated important in terms of severity, score 7.8 out of 10 on the CVSS scale, and involve abusing memory-safety bugs: Two use-after-free, and one heap buffer overflow.<\/p>\n

That\u2019s scary because they can allow an attacker to gain SYSTEM privileges \u2013 the ultimate position of power on a Windows box. That said, the vulnerabilities are not billed as guest escapes, and instead we’re told they simply allow a rogue user or malware already on a machine to gain top privileges. Whatever the problem is, it’s present in Windows 10 and 11, plus Windows Server\u2019s 2022 and 2025 releases.<\/p>\n