CVE-2019-0803
Published: November 3, 2021
Official Description
Microsoft Win32k contains an unspecified vulnerability due to it failing 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 contains an unspecified vulnerability due to it failing 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
An unspecified vulnerability in Microsoft Win32k's memory handling can lead to privilege escalation, allowing an attacker to run code with kernel-level privileges. The very high EPSS score of 0.90302 and its presence in CISA's KEV indicate a critical and actively exploited threat.
This vulnerability is actively exploited in the wild, as confirmed by its inclusion in CISA's Known Exploited Vulnerabilities catalog.
Apply the latest security updates from Microsoft to address this Win32k vulnerability. Regularly patch and update all Windows systems to mitigate similar kernel-level flaws.
Technical Analysis
CVE-2019-0803 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-2019-0803 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-2019-0803 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