# CVE-2020-26933: Security feature bypass in n/a

> Improper initialization during non-orderly shutdown allows bypassing dictionary attack protections in TPM firmware.

- **Severity:** High 7.2 (`CVSS:3.1/AC:H/AV:L/A:N/C:H/I:H/PR:H/S:C/UI:N`)
- **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:** 18 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-988w-p627-h6w6

## What is CVE-2020-26933?

CVE-2020-26933 is a high-severity vulnerability in n/a, published on 18 Nov 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Trusted Computing Group (TCG) Trusted Platform Module Library Family 2.0 Library Specification Revisions 1.38 through 1.59 has Incorrect Access Control during a non-orderly TPM shut-down that uses USE_DA_USED. Improper initialization of this shut-down may result in susceptibility to a dictionary attack.

Weakness: CWE-665 (Improper Initialization)

## Which versions are affected by CVE-2020-26933?

It affects 1 product.


Products: Trustedcomputinggroup Trusted Platform Module.

## How do I fix CVE-2020-26933?

No fix has been published for CVE-2020-26933 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-26933 being exploited?

There is no known exploitation of CVE-2020-26933 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-6622](https://insights.sbomify.com/CVE-2018-6622/): An issue was discovered that affects all producers of BIOS firmware who make a certain realistic interpretation of an obscure portion of the (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-26933 and fix it if it is affected.

What it is: CVE-2020-26933 is a high-severity vulnerability in n/a, published on 18 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-2020-26933 in the wild and no public exploit code.

Affected product: n/a. 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-2020-26933/ (Markdown: https://insights.sbomify.com/CVE-2020-26933/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-26933
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-26933
- OSV: https://osv.dev/vulnerability/CVE-2020-26933

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-26933/
Summaries are generated and may contain mistakes; the official description above is the record.