Reported by Matheus Mariano, a Brazilian software developer, a programming error was discovered in Apple’s most recent operating system, High Sierra, that exposed passwords of encrypted volumes as password hints. A serious bug that quickly made the headlines in technology websites everywhere.
Apple was prompt to provide macOS High Sierra Supplemental Update to customers via the App Store, and ensured that every distribution of High Sierra in their servers included this update.
I decided to apply a binary diffing technique to the update to learn more about the root cause of this bug and hypothesize about how the defect could have been prevented.
Reverse engineering the macOS High Sierra supplemental update
2017-10-09 macOS 6 Comments
As a programmer I fail to find this anything else than another day at the office. Already before reading the article, I assumed that they just stored the password as ‘password hint’, because that’s the only option.
Passwords are usually stored in a form that is not reversible, so it just cannot pop up in another field by accident unless it was deliberately put there.
Programming is still mostly manual work i.e. every little detail has to be written by hand just as we see it happen on the screen. There rarely exists any magical method so that we just type one line of code and see a hundred things happen, no.