CVE-2022-38362: Apache Airflow Docker Provider <3.0 RCE vulnerability in example dag

How it was found

Apache Airflow Docker's Provider shipped with an example DAG that was vulnerable to (authenticated) remote code exploit of code on the Airflow worker host.

Vulnerability summary:

In DAG script of airflow 2.3.3, there is a command injection vulnerability (RCE) in the script (example_docker_copy_data.py of docker provider), which can obtain the permission of the operating system.

source path: airflow-2.3.3/airflow/providers/docker/example_dags/example_docker_copy_data.py

Vulnerability details：

(1) Vulnerability principle：

1. It can be seen from the source code of example_docker_copy_data.py script that there is the function of executing bash command, The parameter ‘source_location’ in the template expression {{params.source_location}} is externally controllable and rendered through the jiaja2 template:

{F1869746}

2. Further analysis “from airflow.operators.bash import BashOperator” code, we can see bash_command parameter value will be executed as a bash script;

{F1869748}

(2)Vulnerability exploit：

1. Enter the DAGs menu and start docker_sample_copy_data task, select “Trigger DAG w/ config”.

http://192.168.3.17:8080/trigger?dag_id=docker_sample_copy_data

{F1869749}

2. To construct payload, we can separate commands with ‘;’, so as to inject any operating system commands to be executed(RCE).

{F1869750}

PAYLOAD：{"source_location":";touch /tmp/thisistest;"}, Then click trigger to execute the task.

{F1869755}

The final command is as follows:

find ;touch /tmp/thisistest; -type f -printf “%f\n” | head -1
“””

Through the log and server view, it can be seen that arbitrary command has been executed successfully.

{F1869756}

{F1869757}

Impact

An attacker can execute arbitrary commands on the airflow host.