# CVE-2021-3453: Security feature bypass in BIOS

> Attackers with physical access can bypass Intel Boot Guard to write to SPI flash, enabling persistent code execution on Lenovo systems.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Jul 2021
- **Updated:** 16 Dec 2025
- **Also known as:** GHSA-rm7h-f39f-xc8f

## What is CVE-2021-3453?

CVE-2021-3453 is a medium-severity vulnerability in Lenovo BIOS, published on 16 Jul 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Some Lenovo Notebook, ThinkPad, and Lenovo Desktop systems have BIOS modules unprotected by Intel Boot Guard that could allow an attacker with physical access the ability to write to the SPI flash storage.

Weakness: CWE-693 (Protection Mechanism Failure)

## Which versions are affected by CVE-2021-3453?

It affects 21 products.


Products: Lenovo 730s-13iml Firmware, Lenovo Ideacentre Aio 5-24imb05 Firmware, Lenovo Ideacentre Aio 5-74imb05 Firmware, Lenovo Ideapad 1-11igl05 Firmware, Lenovo Ideapad 1-14igl05 Firmware, Lenovo Ideapad S940-14iil Firmware, Lenovo Ideapad S940-14iwl Firmware, Lenovo Ideapad Slim 1-11ast-05 Firmware, Lenovo Ideapad Slim 1-14ast-05 Firmware, Lenovo Thinkpad Helix Firmware, Lenovo Thinkpad T550 Firmware, Lenovo Thinkpad W550s Firmware, Lenovo Thinkpad X1 Carbon 3rd Gen Firmware, Lenovo Thinkpad X250 Firmware, Lenovo Thinkpad Yoga 15 Firmware, Lenovo V130-15igm Firmware, Lenovo V330-15ikb Firmware, Lenovo V330-15isk Firmware, Lenovo Yoga S730-13iml Firmware, Lenovo Yoga S940-14iil Firmware and 1 more.

## How do I fix CVE-2021-3453?

No fix has been published for CVE-2021-3453 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-3453 being exploited?

There is no known exploitation of CVE-2021-3453 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3453 and fix it if it is affected.

What it is: CVE-2021-3453 is a medium-severity vulnerability in Lenovo BIOS, published on 16 Jul 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-2021-3453 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-2021-3453/ (Markdown: https://insights.sbomify.com/CVE-2021-3453/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3453
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3453
- OSV: https://osv.dev/vulnerability/CVE-2021-3453

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3453/
Summaries are generated and may contain mistakes; the official description above is the record.