Cyber Resilience

CVE-2021-1661

High

Published: 12 January 2021

Published
12 January 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0027 50.5th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-1661 is a high-severity Improper Initialization (CWE-665) vulnerability in Microsoft Windows 10. Its CVSS base score is 7.8 (High).

Operationally, ranked in the top 49.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Windows Installer Elevation of Privilege Vulnerability

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

microsoft
windows 10
1607, 1803, 1809, 1909, 2004
microsoft
windows 7
all versions
microsoft
windows 8.1
all versions
microsoft
windows rt 8.1
all versions
microsoft
windows server 2008
all versions, r2
microsoft
windows server 2012
all versions, r2
microsoft
windows server 2016
1909, 2004, 20h2, all versions
microsoft
windows server 2019
all versions

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-665

Ensures shared resources are explicitly initialized or cleared on allocation, preventing exposure of prior contents to new users or processes.

addresses: CWE-665

Mandates that every instance begins in a known (presumably clean) state, eliminating reliance on residual or uninitialized state left by prior executions.

References