Apple confirmed this morning that the leaked iOS source code that hit the web yesterday is indeed authentic. Though iOS 9 is a dated version of the company's mobile operating system, it's possible that the leaked code could be used to jailbreak older devices or worse.
What makes this is so interesting - and potentially frightening - is that security researchers and hackers alike will scan through the code to try and find inherent flaws in it. The leak involves proprietary information that Apple works hard to keep secret. Plus, the source code has some files missing, meaning it can't be compiled, but other experts said on Twitter that it could still enable hackers to find exploits and create jailbreaks. It verifies the kernel is signed by Apple and then executes it.
According to these sources, the person who stole the code didn't have an axe to grind with Apple.
The code appeared online on Wednesday, and quickly surprised Apple-watchers with just what had been publicly released. iBoot is Apple's bootloader, one of the earliest processes which launches when you first power up an Apple device. Apple itself seems unconcerned about the potential security issues, with the company noting in a statement that the code is already three years old and that "the security of our products doesn't depend on the secrecy of our source code".
IT security consultant/hacker Hector Martin downplayed how much of a security risk the iBoot leak could pose for Apple and its customers. That's applies to this case in particular, since the leaked source code is said to contain documentation.
Martin also criticized reports calling the leak the "biggest in history", pointing to past disclosures with far wider-reaching impacts. Microsoft warned at the time that anyone who searching for or sharing such code was engaging in illegal activity, and sent letters to that effect to people who had downloaded the code. Those involved originally say they did all they could to delay a leak until the chance of that coming true was minimized by virtue of new versions of iOS being released.