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CVE-2020-27339

Published: Jun 16, 2021Updated: Nov 4, 2025 Sources: CVE List NVDCWE-20
NVD MITRE
6.7CVSSMEDIUM
EPSS Score
0.3%
Top 76.8%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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).

CVSS Vector Breakdown

AV:LAC:LPR:HUI:NS:UC:HI:HA:H
Exploitability
AV:LAttack Vector
Local
AC:LAttack Complexity
Low
PR:HPrivileges Required
High
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-20

Affected Products

insydeh2oinsyde
EmbeddedFirmware
Hardware Firmware / bios-uefi
ruggedcom apr1808 firmwaresiemensICS / OT / IoT
simatic field pg m5 firmwaresiemensICS / OT / IoT
simatic field pg m6 firmwaresiemensICS / OT / IoT
simatic ipc127e firmwaresiemensICS / OT / IoT
insydecommercialTWHardware Firmwareaka insydeh2o
siemenscommercialDEEnterprise Softwareaka siemens ag
and 13 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

Official Patch Available

MITRE ATT&CK

1 technique
Initial Access
View detailed technique mapping

References

https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf
cert-portal.siemens.com
https://security.netapp.com/advisory/ntap-20220216-0005/
security.netapp.com
https://www.insyde.com/security-pledge/SA-2021001
insyde.com
and 1 more references View all →

Timeline

Published
Jun 16, 2021
Last Updated
Nov 4, 2025

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