Is CVE-2020-27339 in the CISA KEV catalog?

No. CVE-2020-27339 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2020-27339?

CVE-2020-27339 has a CVSS v3 base score of 6.7 (MEDIUM).

What is the EPSS score for CVE-2020-27339?

CVE-2020-27339 has an EPSS score of 0.32% (24th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2020-27339?

Upgrade insydeh2o to 5.43.25 or later.

CVE & CISA-KEV Catalog

CVE-2020-27339

MEDIUM

6.7

CVSS v3

NVD

Description

In the kernel in Insyde InsydeH2O 5.x, certain SMM drivers did not correctly validate the CommBuffer and CommBufferSize parameters, allowing callers to corrupt either the firmware or the OS memory. The fixed versions for this issue in the AhciBusDxe, IdeBusDxe, NvmExpressDxe, SdHostDriverDxe, and SdMmcDeviceDxe drivers are 05.16.25, 05.26.25, 05.35.25, 05.43.25, and 05.51.25 (for Kernel 5.1 through 5.5).

CWE-20Improper Input Validation

How to fix

Remediation Available

insydeh2oNVD

Affected:>= 5.4, < 5.43.25Fixed in:5.43.25CVE-2020-27339derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredHigh

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

0.32%probability of exploitation in 30 days

24thpercentile

Low risk: more likely to be exploited than 24% of all known CVEs.

References

Vendor Advisory1

insyde.com

Third-Party Advisory2

Other references1

kb.cert.org

Related Vulnerabilities

Other CWE-20 (Improper Input Validation) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2024-3400	Critical	10.0	100%	KEV + Ransom	-
CVE-2021-45105	Medium	5.9	100%	-	Fix
CVE-2021-44228	Critical	10.0	100%	KEV + Ransom	Fix
CVE-2021-21985	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2018-7600	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2020-3452	High	7.5	100%	KEV	Fix

Embed a live status badge for CVE-2020-27339

Markdown

[![CVE-2020-27339](https://tridentstack.com/cve/badge/CVE-2020-27339.svg)](https://tridentstack.com/cve/CVE-2020-27339)

HTML

<a href="https://tridentstack.com/cve/CVE-2020-27339"><img src="https://tridentstack.com/cve/badge/CVE-2020-27339.svg" alt="CVE-2020-27339"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-04.