CVE-2019-0859
Published: November 3, 2021
Official Description
Microsoft Win32k fails to properly handle objects in memory causing privilege escalation. Successful exploitation allows an attacker to run code in kernel mode.
CISA KEV Advisory
Microsoft Win32k Privilege Escalation Vulnerability
Microsoft Win32k fails to properly handle objects in memory causing privilege escalation. Successful exploitation allows an attacker to run code in kernel mode.
Apply updates per vendor instructions.
Risk Analysis
Microsoft Win32k has a privilege escalation vulnerability due to improper object handling in memory, allowing an attacker to run code in kernel mode. This high-severity flaw has a significant exploitation probability (EPSS 0.09881), making it a critical concern. This vulnerability is confirmed to be actively exploited by CISA.
Active exploitation of this vulnerability has been observed in the wild. Exploitation typically requires local access or another initial compromise.
Apply all available security updates for Microsoft Windows. Implement robust endpoint detection and response solutions to detect and prevent privilege escalation attempts.
Technical Analysis
CVE-2019-0859 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2019-0859 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2019-0859 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1