# CVE-2023-24621: Esoteric YamlBeans Unsafe Deserialization vulnerability

> Attackers can execute arbitrary code by supplying malicious YAML documents to applications using the YamlBeans library.

- **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:** No
- **Published:** 25 Aug 2023
- **Updated:** 2 Oct 2024
- **Also known as:** GHSA-jm7r-4pg6-gf26

## What is CVE-2023-24621?

CVE-2023-24621 is a high-severity unsafe deserialization vulnerability in n/a, published on 25 Aug 2023. 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

An issue was discovered in Esoteric YamlBeans through 1.15. It allows untrusted deserialisation to Java classes by default, where the data and class are controlled by the author of the YAML document being processed.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2023-24621?

2 open source packages ship an affected version, including com.esotericsoftware.yamlbeans:yamlbeans. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `com.esotericsoftware.yamlbeans:yamlbeans` | Maven | All versions to 1.15 | None |
| `com.esotericsoftware.yamlbeans:yamlbeans` | Maven | All versions to 1.15 | None |

Products: Esotericsoftware Yamlbeans.

## How do I fix CVE-2023-24621?

No fix has been published for CVE-2023-24621 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-24621 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-24621 exists.

## Other vulnerabilities in n/a

- [CVE-2023-24620](https://insights.sbomify.com/CVE-2023-24620/): Esoteric YamlBeans XML Entity Expansion vulnerability (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-24621 and fix it if it is affected.

What it is: CVE-2023-24621 is a high-severity unsafe deserialization vulnerability in n/a, published on 25 Aug 2023. 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-24621 exists.

Affected packages and fixed versions:
- com.esotericsoftware.yamlbeans:yamlbeans (Maven): affected all versions up to 1.15; no fix listed
- com.esotericsoftware.yamlbeans:yamlbeans (Maven): affected all versions up to 1.15; 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-2023-24621/ (Markdown: https://insights.sbomify.com/CVE-2023-24621/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-24621
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-24621
- OSV: https://osv.dev/vulnerability/CVE-2023-24621

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-24621/
Summaries are generated and may contain mistakes; the official description above is the record.