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                                CERT-Renater

                     Note d'Information No. 2024/VULN148
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DATE                : 27/03/2024

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Systems running Apache Airflow versions prior
                                          to 2.8.4.

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https://lists.apache.org/thread/8khb1rtbznh100o325fb8xw5wjvtv536
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CVE-2024-29735: Apache Airflow: Potentially harmful permission
changing by log task handler

Severity: important

Affected versions:

- Apache Airflow 2.8.2 through 2.8.3

Description:

Improper Preservation of Permissions vulnerability in Apache Airflow.
his issue affects Apache Airflow from 2.8.2 through 2.8.3.

Airflow's local file task handler in Airflow incorrectly set
permissions for all parent folders of log folder, in default
configuration adding write access to Unix group of the folders. In
the case Airflow is run with the root user (not recommended) it added
group write permission to all folders up to the root of the filesystem.

If your log files are stored in the home directory, these permission
changes might impact your ability to run SSH operations after your
home directory becomes group-writeable.

This issue does not affect users who use or extend Airflow using
Official Airflow Docker reference images
( https://hub.docker.com/r/apache/airflow/ ) - those images require
to have group write permission set anyway.

You are affected only if you install Airflow using local
installation / virtualenv or other Docker images, but the issue
has no impact if docker containers are used as intended, i.e.
where Airflow components do not share containers with other
applications and users.

Also you should not be affected if your umask is 002 (group
write enabled) - this is the default on many linux systems.

Recommendation for users using Airflow outside of the containers:

   *  if you are using root to run Airflow, change your Airflow
user to use non-root
   *  upgrade Apache Airflow to 2.8.4 or above
   *  If you prefer not to upgrade, you can change the 
https://airflow.apache.org/docs/apache-airflow/stable/configurations-ref.html#file-task-handler-new-folder-permissions
to 0o755 (original value 0o775).

   *  if you already ran Airflow tasks before and your default
umask is 022 (group write disabled) you should stop Airflow
components, check permissions of AIRFLOW_HOME/logs in all your
components and all parent directories of this directory and
remove group write access for all the parent directories


Credit:

Matej Murin (finder)


References:

https://github.com/apache/airflow/pull/37310
https://airflow.apache.org/
https://www.cve.org/CVERecord?id=CVE-2024-29735


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