CSS Exfil Protection

CSS Exfil Protection: Browser Extension & Firewall Module

Prevents sensitive data exfiltration through CSS requests, analyzing and blocking suspicious CSS rules, with a browser extension and firewall module for enhanced security.

What is CSS Exfil Protection?

CSS Exfil Protection is a browser extension and firewall module designed to prevent sensitive data exfiltration through CSS requests. It works by analyzing CSS rules used on websites and blocking any suspicious ones that could potentially allow data exfiltration.

The extension hooks into the browser and scans all CSS files loaded on websites visited by the user. It checks for CSS rules that reference remote resources in ways that could allow sensitive data to be sent cross-domain without the usual restrictions. For example, it would block rules that use URL encodings or other sneaky tricks to hide exfiltration attempts.

The firewall module provides network-level protection as well by scanning outbound CSS requests and stopping any trying to send unauthorized data cross-domain. It maintains allowlists of legitimate domains and blocks requests to all others.

Together, the browser extension and firewall module provide robust protection against CSS data exfiltration attempts. They prevent users from accidentally visiting sites using CSS to steal sensitive data like CSRF tokens or login credentials and transmitting them to attacker-controlled domains. For maximum security, CSS Exfil Protection should be used alongside other protective measures.

CSS Exfil Protection Features

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