# CVE-2020-12926: Race condition in AMD's fTPM implementation

> Physical attackers can exploit a race condition in AMD fTPM to compromise keys, modify signed executables, or cause denial of service.

- **Severity:** Medium 6.4 (`CVSS:3.1/AV:P/AC:H/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:** 12 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-898h-342v-mpjx

## What is CVE-2020-12926?

CVE-2020-12926 is a medium-severity vulnerability in AMD's fTPM implementation, published on 12 Nov 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The Trusted Platform Modules (TPM) reference software may not properly track the number of times a failed shutdown happens. This can leave the TPM in a state where confidential key material in the TPM may be able to be compromised. AMD believes that the attack requires physical access of the device because the power must be repeatedly turned on and off. This potential attack may be used to change confidential information, alter executables signed by key material in the TPM, or create a denial of service of the device.

Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition)

## Which versions are affected by CVE-2020-12926?

It affects 1 product.


Products: Amd Trusted Platform Modules Reference.

## How do I fix CVE-2020-12926?

No fix has been published for CVE-2020-12926 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-12926 being exploited?

There is no known exploitation of CVE-2020-12926 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-12926 and fix it if it is affected.

What it is: CVE-2020-12926 is a medium-severity vulnerability in AMD's fTPM implementation, published on 12 Nov 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-2020-12926 in the wild and no public exploit code.

Affected product: AMD's fTPM implementation. 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-2020-12926/ (Markdown: https://insights.sbomify.com/CVE-2020-12926/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-12926
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-12926
- OSV: https://osv.dev/vulnerability/CVE-2020-12926

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-12926/
Summaries are generated and may contain mistakes; the official description above is the record.