# CVE-2021-3599: Privilege escalation in ThinkPad BIOS

> Local attackers with elevated privileges can execute arbitrary code via a flaw in the ThinkPad BIOS SMI callback function.

- **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:** 12 Nov 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-7jgm-fxw4-3rp9

## What is CVE-2021-3599?

CVE-2021-3599 is a medium-severity vulnerability in Lenovo ThinkPad BIOS, published on 12 Nov 2021. 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 to access flash device in some ThinkPad 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-2021-3599?

It affects 133 products.


Products: Lenovo Ideapad S940-14iwl Firmware, Lenovo Ideapad Yoga S940-14iwl Firmware, Lenovo Thinkpad 10 Firmware, Lenovo Thinkpad 11e 3rd Gen Firmware, Lenovo Thinkpad 11e 4th Gen Firmware, Lenovo Thinkpad 11e Yoga Gen 6 Firmware, Lenovo Thinkpad 13 Gen 2 Firmware, Lenovo Thinkpad 25 Firmware, Lenovo Thinkpad E14 Firmware, Lenovo Thinkpad E14 Gen 2 Firmware, Lenovo Thinkpad E14 Gen 3 Firmware, Lenovo Thinkpad E15 Firmware, Lenovo Thinkpad E15 Gen 2 Firmware, Lenovo Thinkpad E15 Gen 3 Firmware, Lenovo Thinkpad E470 Firmware, Lenovo Thinkpad E480 Firmware, Lenovo Thinkpad E490 Firmware, Lenovo Thinkpad E570 Firmware, Lenovo Thinkpad E580 Firmware, Lenovo Thinkpad E590 Firmware and 113 more.

## How do I fix CVE-2021-3599?

No fix has been published for CVE-2021-3599 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-3599 being exploited?

There is no known exploitation of CVE-2021-3599 in the wild and no public exploit code.

## Other vulnerabilities in Lenovo ThinkPad BIOS

- [CVE-2021-3786](https://insights.sbomify.com/CVE-2021-3786/): Information disclosure in Notebook and ThinkPad BIOS (medium 4.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3599 and fix it if it is affected.

What it is: CVE-2021-3599 is a medium-severity vulnerability in Lenovo ThinkPad BIOS, published on 12 Nov 2021. 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-2021-3599 in the wild and no public exploit code.

Affected product: Lenovo ThinkPad 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-2021-3599/ (Markdown: https://insights.sbomify.com/CVE-2021-3599/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3599
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3599
- OSV: https://osv.dev/vulnerability/CVE-2021-3599

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3599/
Summaries are generated and may contain mistakes; the official description above is the record.