The iPhone 5S and the iPad Air can both be cracked using Luca Todesco's Yalu jailbreaking tool and this is especially true for the mentioned devices that still run on iOS 10.2.1. The same applies for users beta testing version 10.3 of Apple's mobile OS.
In a report, iDownloadBlog.com said that a workaround is now available for iPhone 5S and iPad Air users who want to get a taste of Todesco's Yalu jailbreak. The chance is higher though that the 5S can be modified using the same tool created by the Italian iOS security researcher.
To be clear, there are specific conditions before going through the jailbreak process. First, the device has to be running on iOS 10.2.1 or beta 1 of version 10.3. According to WCCFTech, beta 3 of 10.3 is now ready to download but since the fix is not sure to work with the build it's best to stick with the first beta for now.
Then there has to be the so-called "colliding nonces" that according to iDB can be found on the iPhone 5S running either on iOS 10.2.1 or 10.3 beta 1, and in some cases but not always on the iPad Air (also with the same iOS versions).
Also, users of these devices need to have their 10.2 .SHSH2 blobs saved with the correct colliding nonces. All these conditions present, the jailbreak process can commence.
The first step would be to downgrade from the existing iOS version to 10.2 and the tool to help on this is "futurerestore," according to iDB. It's fairly sure that if the colliding nonces mentioned above are found on the iPhone 5S or iPad Air, the downgrade move should pose no problem at all.
As the same report recommended, "provided you are fortunate enough to have the requisite blobs and have the technical savvy to use the tool, I'd advise you to give it a go now rather than stay stuck on iOS 10.2.1." And there is a fallback in case the process failed to work.
Simply opt for a full restore of the device with the use of iTunes and go back to iOS 10.2.1, which iDB said is still very much possible as the OS version remains in the signed list by Apple. Then wait out.
For what? In recent days, Todesco has announced that he will finalized the Yalu jailbreak while Cydia creator Saurik hinted of an ongoing work that hopefully will rid the iOS 10.2 JB tool of its 7-day certification issue. These promises should be fulfilled soon, meaning there will be better jailbreaking ahead.