# CVE-2021-21638: CSRF vulnerability in Jenkins Team Foundation Server Plugin allow capturing credentials

> Attackers can exploit CSRF to connect to malicious URLs using stolen credentials, capturing stored Jenkins credentials.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 30 Mar 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-263q-5pj7-j6hj

## What is CVE-2021-21638?

CVE-2021-21638 is a high-severity vulnerability in Jenkins Team Foundation Server Plugin, published on 30 Mar 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A cross-site request forgery (CSRF) vulnerability in Jenkins Team Foundation Server Plugin 5.157.1 and earlier allows attackers to connect to an attacker-specified URL using attacker-specified credentials IDs obtained through another method, capturing credentials stored in Jenkins.

Weakness: CWE-352 (Cross-Site Request Forgery)

## Which versions are affected by CVE-2021-21638?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.jenkins-ci.plugins:tfs` | Maven | All versions to 5.157.1 | None |
| `org.jenkins-ci.plugins:tfs` | Maven | All versions to 5.157.1 | None |

Products: Jenkins Team Foundation Server.

## How do I fix CVE-2021-21638?

No fix has been published for CVE-2021-21638 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-21638 being exploited?

There is no known exploitation of CVE-2021-21638 in the wild and no public exploit code.

## Other vulnerabilities in Jenkins Team Foundation Server Plugin

- [CVE-2021-21637](https://insights.sbomify.com/CVE-2021-21637/): Missing permission check in Jenkins Team Foundation Server Plugin allow capturing credentials (medium 6.5)
- [CVE-2021-21636](https://insights.sbomify.com/CVE-2021-21636/): Missing permission check in Jenkins Team Foundation Server Plugin allows enumerating credentials IDs (medium 4.3)
- [CVE-2020-2249](https://insights.sbomify.com/CVE-2020-2249/): Credentials stored in plain text by Jenkins tfs Plugin (low 3.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21638 and fix it if it is affected.

What it is: CVE-2021-21638 is a high-severity vulnerability in Jenkins Team Foundation Server Plugin, published on 30 Mar 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-21638 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.jenkins-ci.plugins:tfs (Maven): affected all versions up to 5.157.1; no fix listed
- org.jenkins-ci.plugins:tfs (Maven): affected all versions up to 5.157.1; no fix listed

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-2021-21638/ (Markdown: https://insights.sbomify.com/CVE-2021-21638/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21638
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21638
- OSV: https://osv.dev/vulnerability/CVE-2021-21638

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21638/
Summaries are generated and may contain mistakes; the official description above is the record.