Cyber Resilience

CVE-2021-31970

MediumPublic PoC

Published: 08 June 2021

Published
08 June 2021
Modified
21 November 2024
KEV Added
—
Patch
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CVSS Score v3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0080 74.5th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-31970 is a medium-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Microsoft Windows 10. Its CVSS base score is 5.5 (Medium).

Operationally, ranked in the top 25.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

Windows TCP/IP Driver Security Feature Bypass Vulnerability

CWE(s)
NVD-CWE-noinfoCWE-639

Related Threats

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

Affected Assets

microsoft
windows 10
1607, 1809, 1909, 2004, 20h2
microsoft
windows 8.1
all versions
microsoft
windows rt 8.1
all versions
microsoft
windows server 2012
all versions, r2
microsoft
windows server 2016
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.

AC-24 Access Control Decisions
addresses: CWE-639

Per-request decision making makes it harder to bypass authorization using user-controlled keys without proper validation in the decision process.

AC-3 Access Enforcement
addresses: CWE-639

Consistent enforcement of approved authorizations makes bypassing via user-controlled keys ineffective.

References