---
id: CVE-2021-41838
title: >-
  An issue was discovered in SdHostDriver in the kernel 5.0 through 5.5 in
  Insyde InsydeH2O
summary: >-
  An issue was discovered in SdHostDriver in the kernel 5.0 through 5.5 in
  Insyde InsydeH2O. There is an SMM callout that allows an attacker to access
  the System Management Mode and execute arbitrary code. This occurs because of
  a Numeric …
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-119
vendor: insyde
product: insydeh2o
affected:
  - 'insydeh2o >= 5.1, < 5.16.42'
  - 'insydeh2o >= 5.2, < 5.26.42'
  - 'insydeh2o >= 5.3, < 5.35.42'
  - 'insydeh2o >= 5.4, < 5.43.42'
  - 'insydeh2o >= 5.5, < 5.51.42'
  - simatic_field_pg_m5_firmware
  - simatic_field_pg_m6_firmware
  - simatic_ipc127e_firmware
  - simatic_ipc227g_firmware
  - simatic_ipc277g_firmware
  - simatic_ipc327g_firmware
  - simatic_ipc377g_firmware
  - simatic_ipc427e_firmware
  - simatic_ipc477e_firmware
  - simatic_ipc627e_firmware
  - simatic_ipc647e_firmware
  - simatic_ipc677e_firmware
  - simatic_ipc847e_firmware
  - simatic_itp1000_firmware
patched:
  - insydeh2o 5.51.42
published: '2022-02-03'
updated: '2026-08-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-41838'
references:
  - url: 'https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf'
    label: cve@mitre.org
  - url: 'https://security.netapp.com/advisory/ntap-20220222-0001/'
    label: cve@mitre.org
  - url: 'https://www.insyde.com/security-pledge'
    label: cve@mitre.org
  - url: 'https://www.insyde.com/security-pledge/SA-2022023'
    label: cve@mitre.org
  - url: 'https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20220222-0001/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.insyde.com/security-pledge'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.insyde.com/security-pledge/SA-2022023'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.kb.cert.org/vuls/id/796611'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-306654.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.00303
epssPercentile: 0.2053
ingestedAt: '2026-08-11T16:47:02.009Z'
---

## Overview

An issue was discovered in SdHostDriver in the kernel 5.0 through 5.5 in Insyde InsydeH2O. There is an SMM callout that allows an attacker to access the System Management Mode and execute arbitrary code. This occurs because of a Numeric Range Comparison Without a Minimum Check.

## Affected

- `insydeh2o >= 5.1, < 5.16.42`
- `insydeh2o >= 5.2, < 5.26.42`
- `insydeh2o >= 5.3, < 5.35.42`
- `insydeh2o >= 5.4, < 5.43.42`
- `insydeh2o >= 5.5, < 5.51.42`
- `simatic_field_pg_m5_firmware`
- `simatic_field_pg_m6_firmware`
- `simatic_ipc127e_firmware`
- `simatic_ipc227g_firmware`
- `simatic_ipc277g_firmware`
- `simatic_ipc327g_firmware`
- `simatic_ipc377g_firmware`
- `simatic_ipc427e_firmware`
- `simatic_ipc477e_firmware`
- `simatic_ipc627e_firmware`
- `simatic_ipc647e_firmware`
- `simatic_ipc677e_firmware`
- `simatic_ipc847e_firmware`
- `simatic_itp1000_firmware`

## Remediation

Upgrade past the affected range:

- `insydeh2o 5.51.42`