HTML smuggling explained
Using a combination of HTML5 and JavaScript to sneak malicious files past content filters is not a new offensive technique. This mechanism has been incorporated into popular offensive frameworks such as Demiguise and SharpShooter for example. However, from our discussions and trainings with blue teams, we have learned that many defenders are not aware of this technique or its implications. In this blog post, we will explain how a few lines of JavaScript have big impact on perimeter security.