While Apple waits for a leak that will reveal more information about exactly how the FBI was able to crack the San Bernardino terrorist's iPhone, information obtained through unofficial channels reveals new details about who actually breached its security devices. 
At first, everyone believed that the FBI worked with the Israeli tech company Cellebrite to unlock the iPhone without deleting the data. However, according to a Washington Post publication invoking people who know the issue, the federations actually collaborated with a hacker team.
Apparently a group of hackers contacted the FBI and suggested a different method to unlock the device without losing data after 10 unsuccessful attempts to enter the code access.
All this was allegedly done due to the existence of an unknown vulnerability known to hackers in iOS 9 and Apple does not seem to be aware of it until today. In addition to the specific vulnerability, the hackers reportedly also used a custom-built one hardware to unlock the device securely.
The FBI has promised a reward to hackers who have undertaken to unlock the device, but the exact amount of money they have received is not known.
The Washington Post also says that hackers are part of a group that "hunts for vulnerabilities in software and gives them to the government," and that it was not the first time it has worked with the FBI.
Custom-built hardware used to unlock the San Bernardino iPhone could be the main reason that FBI can not break other devices.
