Apple’s not only apologised for the Error 53 fiasco but issued a new iOS software update to protect against it. However, if you open Settings on your iPhone, and tap General > Update, you’ll be told you’re bang up to date.
Has Apple applied the update while you’re sleeping?
Nope. The update is only available via iTunes on your Mac or PC, so you’ll need to attach your iPhone to the computer via USB, start iTunes, and click the iPhone icon in the top left. Then click the Check for Update button and follow the instructions.
You should do this now, rather than putting it off because who knows when your phone might break and you have to get it urgently repaired?
If you get an error about iTunes being unable to apply the update, reboot your computer and the iPhone, then try again.
Don’t forget to update your iPad Air, iPad Pro and/or iPod Touch (6th gen) too!
iFixIt has confirmed the fix works on iPhones that have been bricked by error 53.