Blog

Persisting XSS With IFrame Traps

XSS Iframe Traps Longer Running XSS Payloads An issue with cross-site scripting (XSS) attacks is that our injected JavaScript might not run for an extended period of time. It may be a reflected XSS vulnerability where we’ve tricked our user into clicking a link, but when they land on the page where we were able...

Persistence Through Service Workers-Part 3: Easy JavaScript Payload Deployment

In “Persistence Through Service Workers—PART 2: C2 Setup and Use,” we demonstrated setting up the Shadow Workers C2 server and how to add both the service worker JavaScript and what Shadow Workers calls the “XSS Payload” JavaScript to the target application. In the example, we didn’t load the “XSS Payload” through a cross-site scripting vulnerability....

Persistence Through Service Workers—Part 2: C2 Setup and Use

In Part 1 of this 2-part blog, we provided an overview of service workers and created an appropriate target application to exploit using Shadow Workers. In this blog post we’ll build our C2 server in Digital Ocean and use Shadow Workers to exploit the target application. It is highly recommended to read Part 1 prior...

Persistence Through Service Workers—Part 1: Introduction and Target Application Setup

During a recent discussion about achieving persistence on a web server, someone suggested that I explore using browser service workers. As I began reading about what service workers do, the possibilities for Red Team applications seemed intriguing. But first, I had to find out…what exactly is a service worker? In their efforts to make web...

Simple Data Exfiltration Through XSS

During a recent engagement, I found a cross-site scripting (XSS) vulnerability in a legal document management application and created a quick and dirty document exfiltration payload. Unfortunately, this discovery and coding happened on the final day of the engagement (*cough* reporting bonus hacking day), and I didn’t have a chance to actually put the exfiltrated...

Setting the ‘Referer’ Header Using JavaScript

Or, “I’m Sorry, You Said You’re from Where Again?” In a prior webinar on creating weaponized Cross-Site Scripting (XSS) payloads, I mentioned that XSS payloads (written in JavaScript) could not change the HTTP Referer header. Malicious requests made through an XSS payload will often have an unexpected Referer header that does not generally make sense...