XSS in Gmail's Amp4Email
Background AMP is most commonly used as a framework to develop fast-loading content on the web. One of AMP's projects, AMP4Email has been adopted in recent years by many of the leading mail services as a way to provide Dynamic Emails (essentially a subset of regular HTML with a few default components to handle things like layouts, templates, forms, and such). When I first heard about this feature a few years ago, my initial reaction (like many of you I’m sure) was “This can’t be secured! How did
