Collected research
Blind CSS Exfiltration: exfiltrate unknown web pages
With only CSS injected into a page whose structure the attacker cannot see, attribute selectors combined with :has and :not on the html element, CSS variable fallbacks and multiple backgrounds, and @import chaining let an attacker enumerate and exfiltrate input names and values, textarea names, form actions and anchor links, even where CSP or DOMPurify rules out JavaScript.
Record
- Researcher
- Gareth Heyes
- Published by
- PortSwigger Research
- Date
- Topic
- XSS
In the archive
Related sources
- Presentation slides Whitepaper
- Research tool
- Earlier CSS injection technique Whitepaper
- Gareth Heyes – Blind CSS Exfiltration: Stealing user data from unknown web pages via CSS
Tags
This page is the archive's own catalogue record. The research is the work of Gareth Heyes, first published at the original source. Preserved copies are kept so the citation survives its host; this one was last captured on .