# CVE-2021-41840: Code injection in n/a

> An SMM callout vulnerability in InsydeH2O firmware allows attackers to execute arbitrary code in System Management Mode, requiring firmware updates.

- **Severity:** High 8.2 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Feb 2022
- **Updated:** 11 Aug 2026
- **Also known as:** GHSA-9fr3-m8v5-v6g9

## What is CVE-2021-41840?

CVE-2021-41840 is a high-severity code injection vulnerability in Insyde Insydeh2o, published on 3 Feb 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An issue was discovered in NvmExpressDxe 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 Inclusion of Functionality from an Untrusted Control Sphere.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2021-41840?

It affects 1 product.


Products: Insyde Insydeh2o.

## How do I fix CVE-2021-41840?

No fix has been published for CVE-2021-41840 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-41840 being exploited?

There is no known exploitation of CVE-2021-41840 in the wild and no public exploit code.

## Other vulnerabilities in Insyde Insydeh2o

- [CVE-2021-41842](https://insights.sbomify.com/CVE-2021-41842/): Missing authorization in n/a (critical 9.8)
- [CVE-2023-22612](https://insights.sbomify.com/CVE-2023-22612/): Memory corruption in n/a (high 8.8)
- [CVE-2023-22613](https://insights.sbomify.com/CVE-2023-22613/): Memory corruption in n/a (high 8.8)
- [CVE-2023-22614](https://insights.sbomify.com/CVE-2023-22614/): Memory corruption in n/a (high 8.8)
- [CVE-2023-22615](https://insights.sbomify.com/CVE-2023-22615/): Memory corruption in n/a (high 8.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-41840 and fix it if it is affected.

What it is: CVE-2021-41840 is a high-severity code injection vulnerability in Insyde Insydeh2o, published on 3 Feb 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-41840 in the wild and no public exploit code.

Affected product: Insyde Insydeh2o. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-41840/ (Markdown: https://insights.sbomify.com/CVE-2021-41840/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-41840
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-41840
- OSV: https://osv.dev/vulnerability/CVE-2021-41840

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-41840/
Summaries are generated and may contain mistakes; the official description above is the record.