Cyber Resilience

CVE-2021-38578

High

Published: 03 March 2022

Published
03 March 2022
Modified
03 November 2025
KEV Added
—
Patch
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CVSS Score v3.1 7.4 CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L
EPSS Score 0.0006 20.0th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-38578 is a high-severity Buffer Underflow (CWE-124) vulnerability in Insyde Kernel. Its CVSS base score is 7.4 (High).

Operationally, ranked at the 20.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Existing CommBuffer checks in SmmEntryPoint will not catch underflow when computing BufferSize.

CWE(s)
CWE-124CWE-787

Related Threats

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

Affected Assets

tianocore
edk2
≤ 202202
insyde
kernel
5.0, 5.1, 5.2, 5.3, 5.4

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.

SI-16 Memory Protection
addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

References