# CVE-2021-30180: Apache Dubbo RCE on customers via Condition route poisoning (Unsafe YAML unmarshaling)

> Attackers can achieve remote code execution by poisoning YAML routing rules in Apache Dubbo when tag routing is enabled.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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:** Not needed
- **Fix available:** Yes
- **Published:** 31 May 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-7wfc-x4f7-gg2x

## What is CVE-2021-30180?

CVE-2021-30180 is a critical unsafe deserialization vulnerability in Apache Dubbo, published on 31 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Apache Dubbo prior to 2.7.9 support Tag routing which will enable a customer to route the request to the right server. These rules are used by the customers when making a request in order to find the right endpoint. When parsing these YAML rules, Dubbo customers may enable calling arbitrary constructors.

Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests)

## Which versions are affected by CVE-2021-30180?

2 open source packages ship an affected version, including org.apache.dubbo:dubbo. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.apache.dubbo:dubbo` | Maven | From 2.7.0 | 2.7.10 |
| `org.apache.dubbo:dubbo` | Maven | From 2.7.0 | 2.7.10 |

Products: Apache Dubbo.

## How do I fix CVE-2021-30180?

Upgrade org.apache.dubbo:dubbo to 2.7.10 or later.

## Is CVE-2021-30180 being exploited?

There is no known exploitation of CVE-2021-30180 in the wild and no public exploit code.

Public exploit code:

- https://github.com/shoucheng3/apache__dubbo_CVE-2021-30180_2-7-9 (github_poc): https://github.com/shoucheng3/apache__dubbo_CVE-2021-30180_2-7-9

## Other vulnerabilities in Apache Dubbo

- [CVE-2023-29234](https://insights.sbomify.com/CVE-2023-29234/): Bypass serialize checks in Apache Dubbo (critical 9.8)
- [CVE-2023-46279](https://insights.sbomify.com/CVE-2023-46279/): Apache Dubbo: Bypass deny serialize list check in Apache Dubbo (critical 9.8)
- [CVE-2021-32824](https://insights.sbomify.com/CVE-2021-32824/): Regular expression Denial of Service in MooTools (critical 9.8)
- [CVE-2022-39198](https://insights.sbomify.com/CVE-2022-39198/): Apache Dubbo Hession Deserialization Vulnerability Gadgets Bypass (critical 9.8)
- [CVE-2021-43297](https://insights.sbomify.com/CVE-2021-43297/): Dubbo Hessian cause RCE when parse error (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-30180 and fix it if it is affected.

What it is: CVE-2021-30180 is a critical unsafe deserialization vulnerability in Apache Dubbo, published on 31 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-30180 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.apache.dubbo:dubbo (Maven): affected from 2.7.0; fixed in 2.7.10
- org.apache.dubbo:dubbo (Maven): affected from 2.7.0; fixed in 2.7.10

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-2021-30180/ (Markdown: https://insights.sbomify.com/CVE-2021-30180/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-30180
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-30180
- OSV: https://osv.dev/vulnerability/CVE-2021-30180

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-30180/
Summaries are generated and may contain mistakes; the official description above is the record.