# CVE-2021-46364: Deserialization of Untrusted Data in Magnolia CMS

> Attackers can execute arbitrary code in Magnolia CMS by submitting a crafted YAML file due to unsafe deserialization in the Snake YAML parser.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/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:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 11 Feb 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-pwr6-p3fh-grc2

## What is CVE-2021-46364?

CVE-2021-46364 is a high-severity unsafe deserialization vulnerability in n/a, published on 11 Feb 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A vulnerability in the Snake YAML parser of Magnolia CMS v6.2.3 and below allows attackers to execute arbitrary code via a crafted YAML file.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2021-46364?

2 open source packages ship an affected version, including info.magnolia:magnolia-core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `info.magnolia:magnolia-core` | Maven | All versions | 6.2.4 |
| `info.magnolia:magnolia-core` | Maven | All versions | 6.2.4 |

Products: Magnolia-Cms Magnolia Cms.

## How do I fix CVE-2021-46364?

Upgrade info.magnolia:magnolia-core to 6.2.4 or later.

## Is CVE-2021-46364 being exploited?

There is no known exploitation of CVE-2021-46364 in the wild and no public exploit code.

Public exploit code:

- CVE-2021-46364: YAML Deserialization in Magnolia CMS (github_poc): https://github.com/mbadanoiu/CVE-2021-46364

## Other vulnerabilities in n/a

- [CVE-2021-46361](https://insights.sbomify.com/CVE-2021-46361/): Arbitrary code execution in Magnolia CMS (critical 9.8)
- [CVE-2021-46362](https://insights.sbomify.com/CVE-2021-46362/): Code injection in n/a (critical 9.8)
- [CVE-2021-46366](https://insights.sbomify.com/CVE-2021-46366/): Cross-Site Request Forgery in Magnolia CMS (high 8.8)
- [CVE-2021-46363](https://insights.sbomify.com/CVE-2021-46363/): Arbitrary code execution in Magnolia CMS (high 7.8)
- [CVE-2021-46365](https://insights.sbomify.com/CVE-2021-46365/): Improper Restriction of XML External Entity Reference in Magnolia CMS (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-46364 and fix it if it is affected.

What it is: CVE-2021-46364 is a high-severity unsafe deserialization vulnerability in n/a, published on 11 Feb 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-46364 in the wild and no public exploit code.

Affected packages and fixed versions:
- info.magnolia:magnolia-core (Maven): affected all versions; fixed in 6.2.4
- info.magnolia:magnolia-core (Maven): affected all versions; fixed in 6.2.4

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-2021-46364/ (Markdown: https://insights.sbomify.com/CVE-2021-46364/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-46364
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-46364
- OSV: https://osv.dev/vulnerability/CVE-2021-46364

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-46364/
Summaries are generated and may contain mistakes; the official description above is the record.