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CVE-2021-33626

Published: Oct 1, 2021Updated: Nov 4, 2025 Sources: CVE List NVDCWE-829
NVD MITRE
7.8CVSSHIGH
EPSS Score
0.3%
Top 78.9%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

A vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate the allocated buffer pointer(QWORD values for CommBuffer). This can be used by an attacker to corrupt data in SMRAM memory and even lead to arbitrary code execution.

CVSS Vector Breakdown

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

Weaknesses

CWE-829

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-20220216-0006/
security.netapp.com
https://www.insyde.com/security-pledge
insyde.com
and 2 more references View all →

Timeline

Published
Oct 1, 2021
Last Updated
Nov 4, 2025

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