MetaMask – Crypto Wallet Firefox extension security report

This permission enables the extension to monitor and analyze all web requests made by the browser. Rated Critical because it can observe all network traffic including sensitive data, track browsing behavior, and gather authentication tokens.

This permission allows the extension to intercept, modify, or block any web request in real-time before it reaches its destination. Rated Critical because it can modify sensitive data (like passwords, credit cards) before encryption, redirect traffic to malicious sites, or block security updates.

Broad host access — the extension can read/modify content on every website.

Broad host access — the extension can read/modify content on every website.

Allows extensions to intercept web requests, manage cookies, and access identity or certificate-related functionalities, potentially compromising secure access and authentication processes.

This extension can intercept, modify, and block web requests in real-time.

This permission allows modification of clipboard content. Rated High because it can inject malicious content into the clipboard, modify copied passwords, and manipulate copied data.

This permission accesses Chrome identity service and user information. Rated High because it can obtain OAuth tokens, access connected accounts, and impersonate the user in authenticated service.

This permission provides full access to read and modify browser cookies. Rated High because it can steal session tokens, modify authentication cookies, and compromise accounts across websites.

The following context increases the overall risk:• 20% increase: Access to sensitive domains increases potential impact• 10% increase: Early script execution enables pre-emptive content manipulation• 15% increase: Older manifest version lacks modern security controls

This permission allows storing data locally in the browser. Rated Medium because it can persist sensitive user data, track user activities over time, and potentially store malicious payloads.

This permission removes storage quota restrictions. Rated Medium because it can store large amounts of user data without limits, potentially impacting browser performance and storing extensive tracking data.

This permission grants temporary access to the current tab. Rated Medium because it can access current page content when invoked, though limited to user-initiated actions.

Host permission — access limited to this URL pattern.

Host permission — access limited to this URL pattern.

Host permission — access limited to this URL pattern.

This extension requests access to sensitive domains: *://connect.trezor.io/*/popup.html*

This extension runs content scripts at document_start.

This extension uses Manifest Version 2

This permission displays system notifications. Rated Low because it can only show user-visible notifications without accessing system data.