# CVE-2021-4212: Code injection in BIOS

> An attacker with local elevated privileges can execute arbitrary code via a vulnerability in the Lenovo Notebook BIOS Legacy BIOS mode driver.

- **Severity:** Medium 6.7 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/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:** 22 Apr 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-937r-586h-vgqf

## What is CVE-2021-4212?

CVE-2021-4212 is a medium-severity code injection vulnerability in Lenovo BIOS, published on 22 Apr 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A potential vulnerability in the SMI callback function used in the Legacy BIOS mode driver in some Lenovo Notebook models may allow an attacker with local access and elevated privileges to execute arbitrary code.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2021-4212?

It affects 62 products.


Products: Lenovo C340-14iml Firmware, Lenovo C340-15iml Firmware, Lenovo D330-10igm Firmware, Lenovo Duet 3-10igl5 Firmware, Lenovo E41-50 Firmware, Lenovo Flex-14iml Firmware, Lenovo Flex-15iml Firmware, Lenovo Ideapad 3-14are05 Firmware, Lenovo Ideapad 3-15are05 Firmware, Lenovo Ideapad 3-17are05 Firmware, Lenovo Ideapad 5-14alc05 Firmware, Lenovo Ideapad 5-14are05 Firmware, Lenovo Ideapad 5-15itl05 Firmware, Lenovo Ideapad 5 Pro-14acn6 Firmware, Lenovo Ideapad 5 Pro-14itl6 Firmware, Lenovo Ideapad 5 Pro-16ihu6 Firmware, Lenovo Ideapad Creator 5-15imh05 Firmware, Lenovo Ideapad Gaming 3-15ach6 Firmware, Lenovo Ideapad Gaming 3-15arh05 Firmware, Lenovo Ideapad Gaming 3-15imh05 Firmware and 42 more.

## How do I fix CVE-2021-4212?

No fix has been published for CVE-2021-4212 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-4212 being exploited?

There is no known exploitation of CVE-2021-4212 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-4212 and fix it if it is affected.

What it is: CVE-2021-4212 is a medium-severity code injection vulnerability in Lenovo BIOS, published on 22 Apr 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-2021-4212 in the wild and no public exploit code.

Affected product: Lenovo BIOS. 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-2021-4212/ (Markdown: https://insights.sbomify.com/CVE-2021-4212/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-4212
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-4212
- OSV: https://osv.dev/vulnerability/CVE-2021-4212

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-4212/
Summaries are generated and may contain mistakes; the official description above is the record.