CVE-2021-34486
Published: 12 August 2021
Summary
CVE-2021-34486 is a high-severity Use After Free (CWE-416) vulnerability in Microsoft Windows 10 1809. Its CVSS base score is 7.8 (High).
Operationally, ranked in the top 2.8% 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 SI-2 (Flaw Remediation) and AC-6 (Least Privilege).
Deeper analysis
Windows Event Tracing contains an elevation of privilege vulnerability tracked as CVE-2021-34486 and assigned CWE-416 for use-after-free. The flaw affects the Windows Event Tracing component and carries a CVSS 3.1 base score of 7.8 reflecting local attack vector, low complexity, low privileges required, and high impact on confidentiality, integrity, and availability.
A local attacker with low privileges can exploit the condition without user interaction to execute arbitrary code with elevated rights on the affected system. Successful exploitation grants the attacker full control over the compromised host.
Microsoft's security advisory and the CISA Known Exploited Vulnerabilities catalog both reference this issue, confirming that patches are available through standard Windows update channels and that the vulnerability has been observed in active exploitation.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-21140
Vulnerability details
Windows Event Tracing Elevation of Privilege Vulnerability
- CWE(s)
- KEV Date Added
- 28 March 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 application of vendor patches that remediate the use-after-free flaw in Windows Event Tracing.
Enforces least-privilege restrictions that limit the initial low-privilege context an attacker must obtain before exploiting the EoP.
Implements memory-protection mechanisms that can block or complicate exploitation of the CWE-416 use-after-free condition.