CVE-2021-40450
Published: 13 October 2021
Summary
CVE-2021-40450 is a high-severity an unspecified weakness vulnerability in Microsoft Windows 10 1809. Its CVSS base score is 7.8 (High).
Operationally, ranked in the top 11.1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
The strongest mitigations our analysis identified are NIST 800-53 AC-6 (Least Privilege) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2021-40450 is a Win32k elevation of privilege vulnerability affecting the Win32k component in Windows. It carries a CVSS 3.1 score of 7.8 reflecting local attack vector, low complexity, low privileges required, and no user interaction, with high impact on confidentiality, integrity, and availability.
An attacker with existing local access and limited privileges can exploit the flaw to elevate rights on the target system, potentially obtaining full administrative control.
Microsoft has published security guidance for the issue via its advisory portal, and the vulnerability appears in CISA's catalog of known exploited vulnerabilities, confirming observed real-world exploitation.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-27627
Vulnerability details
Win32k Elevation of Privilege Vulnerability
- CWE(s)
- KEV Date Added
- 25 April 2022
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires timely installation of the vendor patch that eliminates the Win32k EoP flaw.
Enforces least-privilege boundaries so a locally authenticated low-privileged user cannot reach the vulnerable Win32k code path with sufficient rights to escalate.
Requires the operating system to enforce access-control decisions on kernel objects; the CVE is an implementation failure of that enforcement inside Win32k.