Apple officially dropped iOS 12.1.3 on Tuesday, and it wasn’t long after that security researcher @S0rryMyBad Tweeted a proof of concept (PoC) of the bug used to achieve an iOS 12 jailbreak at the TianfuCup PWN Contest last November.
On Wednesday, @S0rryMyBad followed up with the PoC he Tweeted by publishing a detailed blog post elaborating the ins and outs of his bug, including how it works and how to use it on iOS 12.1.2 and below: