On iPhone 5. Until Apple updates the software to fix the vulnerability.
If they know what to fix. FBI aren't idiots to tell them.
Apple could probably buy the same tool and analyze it.
I was just thinking this. Again, I haven't been able to read the article but I was under the impression that the FBI paid to crack this one phone, I didn't realize that they have this tool that could 'hack' more iPhones with.