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

What is CVE-2021-26559?

CVE-2021-26559 is a medium-severity missing authorization vulnerability in Apache Airflow, published on 17 Feb 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official 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.

Weakness: CWE-284

Which versions are affected by CVE-2021-26559?

4 open source packages ship an affected version, including apache-airflow and airflow. It affects 1 product.

Products include Apache Airflow.

How do I fix CVE-2021-26559?

Upgrade apache-airflow to a fixed version for your release line: 2.0.1 or 2.0.1rc1.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2021-26559 being exploited?

There is no known exploitation of CVE-2021-26559 in the wild and no public exploit code.

Other vulnerabilities in Apache Airflow

• CVE-2020-13927 Apache Airflow's Experimental API Authentication Bypass Exploited Critical 9.8
• CVE-2020-11978 Apache Airflow Command Injection Exploited High 8.8
• CVE-2026-33264 Apache Airflow: DAG author RCE on webserver via unrestricted import_string() in BaseSerialization.deserialize() Critical 9.8
• CVE-2023-25754 Apache Airflow: Privilege escalation using airflow logs Critical 9.8
• CVE-2023-22884 Apache Airflow, Apache Airflow MySQL Provider: Arbitrary file read via MySQL provider in Apache Airflow Critical 9.8

All Apache Airflow vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-airflow-2021-26559, GHSA-ffw3-6mp6-jmvj, PYSEC-2021-2.