========================================= CELERYSA-0002: Celery Security Advisory ========================================= :contact: security@celeryproject.org :CVE id: TBA :date: 2014-07-10 05:00:00 P.M UTC Details ======= :package: celery :vulnerability: Environment error :problem type: local :risk: low :versions-affected: 2.5, 3.0, 3.1 Description =========== The built-in utility used to daemonize the Celery worker service sets an insecure umask by default (umask 0). This means that any files or directories created by the worker will end up having world-writable permissions. In practice this means that local users will be able to modify and possibly corrupt the files created by user tasks. This is not immediately exploitable but can be if those files are later evaluated as a program, for example a task that creates Python program files that are later executed. Patches are now available for all maintained versions (see below), and users are urged to upgrade, even if not directly affected. Acknowledgements ================ Special thanks to Red Hat for originally discovering and reporting the issue. Systems affected ================ Users of Celery versions 3.0, and 3.1, except the recently released 3.1.13, are affected if daemonizing the Celery programs using the `--detach` argument or using the `celery multi` program to start workers in the background, without setting a custom `--umask` argument. Solution ======== NOTE: Not all users of Celery will use it to create files, but if you do then files may already have been created with insecure permissions. So after upgrading, or using the workaround, then please make sure that files already created are not world writable. To work around the issue you can set a custom umask using the ``--umask`` argument: $ celery worker -l info --detach --umask=16 # (022) Or you can upgrade to a more recent version: - Users of the 3.1 series should upgrade to 3.1.13: * ``pip install -U celery``, or * ``easy_install -U celery``, or * http://pypi.python.org/pypi/celery/3.1.13 - Users of the 3.0 series should upgrade to 3.0.25: * ``pip install -U celery==3.0.25``, or * ``easy_install -U celery==3.0.25``, or * http://pypi.python.org/pypi/celery/3.0.25 Distribution package maintainers are urged to provide their users with updated packages. Please direct questions to the celery-users mailing-list: http://groups.google.com/group/celery-users/, or if you are planning to report a new security related issue we request that you keep the information confidential by contacting security@celeryproject.org instead. Thank you!