Affecting passenger gem, versions <5.3.2
passenger is a modern web server and application server for Ruby, Python and Node.js, optimized for performance, low memory usage and ease of use.
Affected versions of this package are vulnerable to Insecure Permissions. Given a Passenger-spawned application process that reports that it listens on a certain Unix domain socket, if any of the parent directories of said socket are writable by a normal user that is not the application's user, then that non-application user can swap that directory with something else, resulting in traffic being redirected to a non-application user's process through an alternative Unix domain socket.
passenger to version 5.3.2 or higher.