# CVE-2020-8335: Security feature bypass in ThinkPad A285 BIOS

> Lenovo ThinkPad BIOS fails to trigger tamper detection when the emergency-reset button is pressed, allowing unauthorized access.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/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:** 1 Sep 2020
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-fvh7-v69p-hj2v

## What is CVE-2020-8335?

CVE-2020-8335 is a medium-severity vulnerability in Lenovo ThinkPad A285 BIOS, published on 1 Sep 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The BIOS tamper detection mechanism was not triggered in Lenovo ThinkPad A285, BIOS versions up to r0xuj70w; A485, BIOS versions up to r0wuj65w; T495 BIOS versions up to r12uj55w; T495s/X395, BIOS versions up to r13uj47w, while the emergency-reset button is pressed which may allow for unauthorized access.

## Which versions are affected by CVE-2020-8335?

It affects 8 products.


Products: Lenovo Thinkpad A275 Firmware, Lenovo Thinkpad A285 Firmware, Lenovo Thinkpad A475 Firmware, Lenovo Thinkpad A485 Firmware, Lenovo Thinkpad T495 Drift Firmware, Lenovo Thinkpad T495s Jazz Firmware, Lenovo Thinkpad X1 Carbon \(20bx\) Firmware, Lenovo Thinkpad X395 Firmware.

## How do I fix CVE-2020-8335?

No fix has been published for CVE-2020-8335 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-8335 being exploited?

There is no known exploitation of CVE-2020-8335 in the wild and no public exploit code.

## Other vulnerabilities in Lenovo ThinkPad A285 BIOS

- [CVE-2020-8334](https://insights.sbomify.com/CVE-2020-8334/): Security feature bypass in BIOS (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-8335 and fix it if it is affected.

What it is: CVE-2020-8335 is a medium-severity vulnerability in Lenovo ThinkPad A285 BIOS, published on 1 Sep 2020. 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-2020-8335 in the wild and no public exploit code.

Affected product: Lenovo ThinkPad A285 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-2020-8335/ (Markdown: https://insights.sbomify.com/CVE-2020-8335/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-8335
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-8335
- OSV: https://osv.dev/vulnerability/CVE-2020-8335

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-8335/
Summaries are generated and may contain mistakes; the official description above is the record.