In this talk I will talk about how can we exploit applications on macOS (including macOS), where some of the directory / file permissions are incorrectly set. The incorrectness of these settings it’s not trivial at first sight because understanding these permissions are not intuitive. We see bugs from simple arbitrary overwrites, to file disclosures and privilege escalation. The concepts applicable to *nix based system as well, however this talk focuses on macOS bugs only.