CVE-2020-27339 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2020-27339MEDIUM

n/a n/a — In the kernel in Insyde InsydeH2O 5.x, certain SMM drivers did not correctly validate the CommBuffer and CommBufferSize parameters, allow…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   H   N  U  H  H  H    6.7   .0032   24.5     —

AFFECTED
  Product  Versions  Fixed
  n/a      n/a –     —

TIMELINE
  Oct 20  Reserved by mitre
  Jun 16  Published (CNA: mitre)
  Aug 11  ENRICHED — CVE-2020-27339. Received CVSS 6.7 and CPE data from NVD.

CWE-20 · CNA: mitre · CVSS v3.1 · 5 references · NVD status: Modified

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).

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
October 20, 2020	Reserved	Reserved by mitre
June 16, 2021	Published	Published (CNA: mitre)
August 11, 2026	ENRICHED	ENRICHED — CVE-2020-27339. Received CVSS 6.7 and CPE data from NVD.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
n/a	n/a	—	n/a	—

Weaknesses

CWE-20

References (5)

https://cert-portal.siemens.com/productcert/html/ssa-306654.html
https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf [Third Party Advisory]
https://security.netapp.com/advisory/ntap-20220216-0005/ [Third Party Advisory]
https://www.insyde.com/security-pledge/SA-2021001 [Vendor Advisory]
https://www.kb.cert.org/vuls/id/796611

Authoritative record: CVE-2020-27339 at cve.org

Weaknesses: CWE-20

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2020-27339 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.