---
id: 5475
title: "uBlock, I exfiltrate: exploiting ad blockers with CSS"
source_domain: portswigger.net
source_url: "https://portswigger.net/research/ublock-i-exfiltrate-exploiting-ad-blockers-with-css"
published_at: "2021-12-07T12:15:00Z"
tags: ["web-security", "css-injection", "ublock-origin", "ad-blockers", "filter-lists", "password-theft"]
phying_url: "https://phying.com/item/5475"
lang: en
---

# uBlock, I exfiltrate: exploiting ad blockers with CSS

## Summary

CSS injection flaws in uBlock Origin's filter rules let crafted filters extract page data and steal Edge passwords; all issues were patched, with compromised filter lists the plausible vector.

## Intelligence Metadata

- **Sources:** portswigger.net
- **Published:** 2021-12-07T12:15:00Z
- **Original:** https://portswigger.net/research/ublock-i-exfiltrate-exploiting-ad-blockers-with-css
- **Phying News:** https://phying.com/item/5475