CVE-2021-33626

HIGH

SMM - Buffer Overflow

Title source: llm
STIX 2.1

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.

Scores

CVSS v3 7.8
EPSS 0.0008
EPSS Percentile 22.9%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-829
Status published
Products (17)
insyde/insydeh2o 5.3 - 5.34.44
siemens/ruggedcom_apr1808_firmware
siemens/simatic_field_pg_m5_firmware
siemens/simatic_field_pg_m6_firmware
siemens/simatic_ipc127e_firmware
siemens/simatic_ipc227g_firmware
siemens/simatic_ipc277g_firmware
siemens/simatic_ipc327g_firmware
siemens/simatic_ipc377g_firmware
siemens/simatic_ipc427e_firmware
... and 7 more
Published Oct 01, 2021
Tracked Since Feb 18, 2026