# CVE-2021-21623: Incorrect permission checks in Jenkins Matrix Authorization Strategy Plugin may allow accessing some items

> Attackers with read access to nested items can bypass parent folder restrictions to view unauthorized content in Jenkins.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/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:** 18 Mar 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-96jw-3xw4-mq9p

## What is CVE-2021-21623?

CVE-2021-21623 is a medium-severity missing authorization vulnerability in Jenkins Matrix Authorization Strategy Plugin, published on 18 Mar 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An incorrect permission check in Jenkins Matrix Authorization Strategy Plugin 2.6.5 and earlier allows attackers with Item/Read permission on nested items to access them, even if they lack Item/Read permission for parent folders.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2021-21623?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.jenkins-ci.plugins:matrix-auth` | Maven | All versions | 2.6.6 |
| `org.jenkins-ci.plugins:matrix-auth` | Maven | All versions | 2.6.6 |

Products: Jenkins Matrix Authorization Strategy.

## How do I fix CVE-2021-21623?

Upgrade org.jenkins-ci.plugins:matrix-auth to 2.6.6 or later.

## Is CVE-2021-21623 being exploited?

There is no known exploitation of CVE-2021-21623 in the wild and no public exploit code.

## Other vulnerabilities in Jenkins Matrix Authorization Strategy Plugin

- [CVE-2026-42521](https://insights.sbomify.com/CVE-2026-42521/): Jenkins Matrix Authorization Strategy Plugin: Unsafe deserialization allows invocation of parameterless constructors (medium 6.5)
- [CVE-2020-2226](https://insights.sbomify.com/CVE-2020-2226/): Stored XSS vulnerability in Jenkins Matrix Authorization Strategy Plugin (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21623 and fix it if it is affected.

What it is: CVE-2021-21623 is a medium-severity missing authorization vulnerability in Jenkins Matrix Authorization Strategy Plugin, published on 18 Mar 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-2021-21623 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.jenkins-ci.plugins:matrix-auth (Maven): affected all versions; fixed in 2.6.6
- org.jenkins-ci.plugins:matrix-auth (Maven): affected all versions; fixed in 2.6.6

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-2021-21623/ (Markdown: https://insights.sbomify.com/CVE-2021-21623/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21623
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21623
- OSV: https://osv.dev/vulnerability/CVE-2021-21623

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21623/
Summaries are generated and may contain mistakes; the official description above is the record.