# CVE-2021-32631: JSON Web Tokens not properly verified

> Attackers can forge valid JSON Web Tokens due to improper signature verification, leading to authentication bypasses in Nimble services.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 Jul 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-fjq8-896w-pv28

## What is CVE-2021-32631?

CVE-2021-32631 is a medium-severity authentication bypass vulnerability in nimble-platform common, published on 26 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Common is a package of common modules that can be accessed by NIMBLE services. Common before commit number 3b96cb0293d3443b870351945f41d7d55cb34b53 did not properly verify the signature of JSON Web Tokens. This allows someone to forge a valid JWT. Being able to forge JWTs may lead to authentication bypasses. Commit number 3b96cb0293d3443b870351945f41d7d55cb34b53 contains a patch for the issue. As a workaround, one may use the parseClaimsJws method to correctly verify the signature of a JWT.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2021-32631?

It affects 1 product.


Products: Nimble-Project Common.

## How do I fix CVE-2021-32631?

No fix has been published for CVE-2021-32631 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-32631 being exploited?

There is no known exploitation of CVE-2021-32631 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-32631 and fix it if it is affected.

What it is: CVE-2021-32631 is a medium-severity authentication bypass vulnerability in nimble-platform common, published on 26 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-32631 in the wild and no public exploit code.

Affected product: nimble-platform common. 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-2021-32631/ (Markdown: https://insights.sbomify.com/CVE-2021-32631/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-32631
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-32631
- OSV: https://osv.dev/vulnerability/CVE-2021-32631

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-32631/
Summaries are generated and may contain mistakes; the official description above is the record.