alf.io has Improper Access Control for Organization Owners that Exposes System Secrets

alf.io is an open source ticket reservation system for conferences, trade shows, workshops, and meetups. An Improper Access Control issue in versions prior to 2.0-M5-2605 allows an organization owner to read system-level configuration secrets through organization/event scoped "single configuration" endpoints. The affected endpoints require organization or event ownership, but they accept an arbitrary configuration key and then return the first matching value from a lookup that includes system-level configuration. As a result, an organization owner can retrieve secrets intended to be administrator-only, including the system API key when it is configured. Version 2.0-M5-2605 fixes the issue.