CVE-2018-8639

A local, authenticated privilege escalation flaw in Windows Win32k allowed attackers to run arbitrary kernel-mode code, leading to ransomware outbreaks.

This vulnerability required local authentication but still enabled arbitrary kernel-mode code execution, a severe breach of trust for any organization running Windows. DIBs must ensure all Windows systems are patched against this KEV-listed flaw to prevent ransomware entry and privilege escalation. The failure highlights the risk of relying on local authentication as a security boundary when a kernel-mode exploit exists.

Shame score — A critical, actively exploited vulnerability in a foundational OS component that enabled ransomware attacks, demonstrating severe negligence in patch management and system hardening.