Apple has stopped signing iOS 11.49 July, Apple released another update of mobile OSes iOS 11.4.1, which included the protection function for USB.
A little more than a week, the company has stopped signing the last iteration of iOS 11.4. To revert to this firmware now impossible.
Previously, the hackers managed to hack iPhone running on iOS 7 11.4 and to carry out the procedure jailbreak. Despite the successful hack attempt, officially, the jailbreak is available only for the operating systems iOS 11.2 — 11.3.1.
Third-party developers are also actively working tool on hacking iOS 11.4.1, but it is unclear whether the jailbreak is ready in the near future. Besides testing the firmware with this sequence number already completed.