# CVE-2021-21661: Missing Authorization in Jenkins Kubernetes CLI Plugin

> Attackers with read permissions can enumerate stored credential IDs due to missing permission checks in the Jenkins Kubernetes CLI Plugin.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/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:** Yes
- **Published:** 10 Jun 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-xrg9-wwrq-xmx9

## What is CVE-2021-21661?

CVE-2021-21661 is a medium-severity missing authorization vulnerability in Jenkins Kubernetes CLI Plugin, published on 10 Jun 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Jenkins Kubernetes CLI Plugin 1.10.0 and earlier does not perform permission checks in several HTTP endpoints, allowing attackers with Overall/Read permission to enumerate credentials IDs of credentials stored in Jenkins.

## Which versions are affected by CVE-2021-21661?

2 open source packages ship an affected version, including org.jenkins-ci.plugins:kubernetes-cli. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.jenkins-ci.plugins:kubernetes-cli` | Maven | All versions | 1.10.1 |
| `org.jenkins-ci.plugins:kubernetes-cli` | Maven | All versions | 1.10.1 |

Products: Jenkins Kubernetes.

## How do I fix CVE-2021-21661?

Upgrade org.jenkins-ci.plugins:kubernetes-cli to 1.10.1 or later.

## Is CVE-2021-21661 being exploited?

There is no known exploitation of CVE-2021-21661 in the wild and no public exploit code.

## Other vulnerabilities in Jenkins Kubernetes CLI Plugin

- [CVE-2018-1999040](https://insights.sbomify.com/CVE-2018-1999040/): Exposure of Sensitive Information in Jenkins Kubernetes Plugin (high 8.8)
- [CVE-2023-30513](https://insights.sbomify.com/CVE-2023-30513/): Jenkins Kubernetes Plugin does not properly mask credentials (high 7.5)
- [CVE-2018-1000187](https://insights.sbomify.com/CVE-2018-1000187/): Exposure of Sensitive Information in Jenkins Kubernetes Plugin (medium 6.5)
- [CVE-2020-2307](https://insights.sbomify.com/CVE-2020-2307/): Exposure of Sensitive Information to an Unauthorized Actor in Jenkins Kubernetes Plugin (medium 4.3)
- [CVE-2020-2308](https://insights.sbomify.com/CVE-2020-2308/): Missing Authorization in Jenkins Kubernetes Plugin (medium 4.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21661 and fix it if it is affected.

What it is: CVE-2021-21661 is a medium-severity missing authorization vulnerability in Jenkins Kubernetes CLI Plugin, published on 10 Jun 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-2021-21661 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.jenkins-ci.plugins:kubernetes-cli (Maven): affected all versions; fixed in 1.10.1
- org.jenkins-ci.plugins:kubernetes-cli (Maven): affected all versions; fixed in 1.10.1

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-2021-21661/ (Markdown: https://insights.sbomify.com/CVE-2021-21661/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21661
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21661
- OSV: https://osv.dev/vulnerability/CVE-2021-21661

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21661/
Summaries are generated and may contain mistakes; the official description above is the record.