Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

Active Storage allows users to attach cloud and local files in Rails applications. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, Active Storage's `DiskService#path_for` does not validate that the resolved filesystem path remains within the storage root directory. If a blob key containing path traversal sequences (e.g. `../`) is used, it could allow reading, writing, or deleting arbitrary files on the server. Blob keys are expected to be trusted strings, but some applications could be passing user input as keys and would be affected. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.