CVE-2021-40449
Published: November 17, 2021
Official Description
Unspecified vulnerability allows for an authenticated user to escalate privileges.
CISA KEV Advisory
Microsoft Windows Win32k Privilege Escalation Vulnerability
Unspecified vulnerability allows for an authenticated user to escalate privileges.
Apply updates per vendor instructions.
Risk Analysis
This unspecified vulnerability allows an authenticated user to escalate privileges on affected systems. The high EPSS score of 0.91304 indicates a very high likelihood of exploitation, making this a critical vulnerability. Its presence in CISA's KEV catalog confirms it has been actively exploited.
This vulnerability is actively exploited in the wild. While it requires prior authentication, its remote exploitability makes it a significant threat.
Apply all available security patches and updates for affected systems to address this privilege escalation vulnerability. Implement the principle of least privilege to minimize the impact of such flaws.
Technical Analysis
CVE-2021-40449 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-2021-40449 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.
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-40449 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