What is CVE-2021-38578?

CVE-2021-38578 is a high-severity vulnerability in Insyde Kernel, classified under Buffer Underwrite. CVSS score: 7.4/10. Published 2022-03-03.

How severe is CVE-2021-38578?

High severity. CVSS v3 base score is 7.4 out of 10.

Is CVE-2021-38578 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Insyde Kernel

CVE-2021-38578

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

Published 2022-03-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L.

EPSS exploit prediction

EPSS: 0.010 (62.7th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 62.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: +0.000

Affected products

Insyde Kernel — versions 5.0, 5.1, 5.2
Tianocore Edk2
Tianocore Edk Ii — versions edk2-stable202208

Weakness classification (CWE)

Public proof-of-concept exploits

w4zu/Debian_

References

bugzilla.tianocore.org/show_bug.cgi (Issue Tracking, Vendor Advisory)
www.insyde.com/security-pledge/SA-2023024 (Third Party Advisory)
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2021-38578?: CVE-2021-38578 is a high-severity vulnerability in Insyde Kernel, classified under Buffer Underwrite. CVSS score: 7.4/10. Published 2022-03-03.
How severe is CVE-2021-38578?: High severity. CVSS v3 base score is 7.4 out of 10.
Is CVE-2021-38578 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.