Apple security flaw: How do ‘zero-click’ attacks work?

Apple users were urged on Sept 14 to update their devices after the tech giant announced a fix for a major software flaw that allows the Pegasus spyware to be installed on phones without so much as a click. — AFP

PARIS: Apple has spent the past week rushing to develop a fix for a major security flaw which allows spyware to be downloaded on an iPhone or iPad without the owner even clicking a button.

But how do such “zero-click” attacks work, and can they be stopped?