Apple products have a reputation for having fewer security problems than just about any other consumer electronics. And that's a deserved reputation, although an increasing number of security holes have been found over the last few years, with five times as much Mac malware detected this year.
In fact, Apple's security is so tough that it can take hackers a long time to find bugs, so most of them concentrate elsewhere. That's why a new company called Zerodium offered a $1 million bounty payable to any hacker or security group that could remotely crack an iPhone running the newest versions of iOS. And someone did.
It was already known that iOS 9 was vulnerable to jailbreaking, which is taking full control of the operating system to run unapproved apps. Every version of iOS has been jailbroken at some point.
However, to do it, you have to have full access to the gadget. Doing a remote jailbreak so you can then install malicious viruses is a completely different story. It requires multiple security flaws to make it work.