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CVE-2021-33627

Published: Feb 3, 2022Updated: Nov 4, 2025 Sources: CVE List NVDCWE-119
NVD MITRE
8.2CVSSHIGH
EPSS Score
0.3%
Top 76.3%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

An issue was discovered in Insyde InsydeH2O Kernel 5.0 before 05.09.11, 5.1 before 05.17.11, 5.2 before 05.27.11, 5.3 before 05.36.11, 5.4 before 05.44.11, and 5.5 before 05.52.11 affecting FwBlockServiceSmm. Software SMI services that use the Communicate() function of the EFI_SMM_COMMUNICATION_PROTOCOL do not check whether the address of the buffer is valid, which allows use of SMRAM, MMIO, or OS kernel addresses.

CVSS Vector Breakdown

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

Weaknesses

CWE-119

Affected Products

n/an/a
insydeh2oinsyde
EmbeddedFirmware
Hardware Firmware / bios-uefi
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 11 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

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://www.insyde.com/security-pledge
insyde.com
https://www.insyde.com/security-pledge/SA-2022022
insyde.com
https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf
cert-portal.siemens.com
and 2 more references View all →

Timeline

Published
Feb 3, 2022
Last Updated
Nov 4, 2025

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