Once inside, click on Service tests > NFC > NFC Diag Test and then hit the home button. You can now browse the phone as normal. We have just tested this on our resident Xperia Z and can confirm the above works without any problems. The lock screen can’t be changed without knowing the passcode or pattern, but you can access all areas of the phone. Let’s hope Sony fixes this exploit as soon as possible.
Via GSM Arena.