Jailbreaking is a method of exploiting a vulnerability in Apple’s iOS.
Exploiting the flaw allows iOS users to have complete control of the core of the operating system, enabling them to do basically anything that the Apple ecosystem forbids. This includes installing any app, customizing the interface, run emulators, and others.
But with each new release of iOS, Apple has made it more and more difficult to jailbreak the OS.
And as it becomes more difficult, the community started to lose hope. Since there haven't been any major and public jailbreak since Apple introduces iOS 10, jailbreaking is having a declining public interest.
This has caused two out of three major Cydia repositories to shut down.
When Google’s Ian Beer announced that he’d be releasing the necessary tools to jailbreak iPhones, the community started seeing a glimpse of hope.
Beer works on Google's Project Zero, a part of Google that focuses in discovering security issues on apps and others, and informing the developers about the problem, helping them to solve the issue.
In Apple's case, Beer found an exploit in iOS 11.1.2 that was fixed on December 2nd. Called "tfp0," he believes that it could be the basis for a future iOS 11.1.2 jailbreaking. On December 11th, 2017, Beer fulfilled his promise by delivering what he found, and tweeted the link to the code.
tfp0 should work for all devices, the PoC local kernel debugger only for those I have to test on (iPhone 7, 6s and iPod Touch 6G) but adding more support should be easy
— Ian Beer (@i41nbeer) December 11, 2017
The community quickly got up on their feet, and hackers began their work, creating a full jailbreak.
But the thing about Beer's finding, is for research purposes only. The exploit works fine with iOS devices running iOS 11.1.2 and below, tvOS 11.x and Apple TV 4K, and Beer said that he tested it on iPhone 7, 6s, and iPod Touch 6G, What this means, "adding more support should be easy."
Jailbreaking is like turning an iOS, making it to behave like Android: enabling users to customize things in a way that is prohibited by Apple. Similar to 'Rooting' on Android, jailbreaking breaks warranty, and as a result, the OS will live without security risks due to the outdated and cracked system.
But for the community, jailbreaking is just the thing. They just love to make their devices to do things they aren’t supposed to do.