---
id: CVE-2021-41837
title: >-
  An issue was discovered in AhciBusDxe in the kernel 5.0 through 5.5 in Insyde
  InsydeH2O
summary: >-
  An issue was discovered in AhciBusDxe in the kernel 5.0 through 5.5 in Insyde
  InsydeH2O. Because of an Untrusted Pointer Dereference that causes SMM memory
  corruption, an attacker may be able to write fixed or predictable data to
  SMRAM. …
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 >= 5.0, < 5.08.41'
  - 'insydeh2o >= 5.1, < 5.16.41'
  - 'insydeh2o >= 5.2, < 5.26.41'
  - 'insydeh2o >= 5.3, < 5.35.41'
  - 'insydeh2o >= 5.4, < 5.43.41'
  - 'insydeh2o >= 5.5, < 5.51.41'
  - 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 5.51.41
published: '2022-02-03'
updated: '2026-08-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-41837'
references:
  - url: 'https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf'
    label: cve@mitre.org
  - url: 'https://security.netapp.com/advisory/ntap-20220222-0003/'
    label: cve@mitre.org
  - url: 'https://www.insyde.com/security-pledge'
    label: cve@mitre.org
  - url: 'https://www.insyde.com/security-pledge/SA-2022024'
    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-20220222-0003/'
    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-2022024'
    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: 0.00281
epssPercentile: 0.18234
ingestedAt: '2026-08-11T16:47:01.812Z'
---

## Overview

An issue was discovered in AhciBusDxe in the kernel 5.0 through 5.5 in Insyde InsydeH2O. Because of an Untrusted Pointer Dereference that causes SMM memory corruption, an attacker may be able to write fixed or predictable data to SMRAM. Exploiting this issue could lead to escalating privileges to SMM.

## Affected

- `insydeh2o >= 5.0, < 5.08.41`
- `insydeh2o >= 5.1, < 5.16.41`
- `insydeh2o >= 5.2, < 5.26.41`
- `insydeh2o >= 5.3, < 5.35.41`
- `insydeh2o >= 5.4, < 5.43.41`
- `insydeh2o >= 5.5, < 5.51.41`
- `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 5.51.41`