Chrome Extension Penetration Testing
Your extension runs inside every page a user visits — with permissions most of those pages never get. We test whether a manifest permission, a content script, or a messaging channel can be turned against the sites it's supposed to protect.
Chrome extension penetration testing, defined
Chrome extension penetration testing is static and dynamic security testing of a Chrome or Chromium-based browser extension — auditing the manifest's declared permissions against what the extension actually uses, tracing content-script injection into page contexts, reviewing messaging between the extension, its background worker, and the page, and checking for remote code loading at runtime.
There's no dedicated OWASP Top 10 for browser extensions — findings map back to Top 10:2025 categories, cross-checked against the Chrome Web Store's extension security best practices and the manifest permissions model.
What we test
- Manifest permission audits — flagging broad host permissions or sensitive API grants the extension's actual functionality doesn't need
- Content-script injection review — whether injected scripts can be exploited by the host page or leak page data back to the extension
- Messaging security —
postMessage,externally_connectableand runtime messaging checked for missing origin validation - Remote code loading — whether the extension fetches and executes code at runtime instead of shipping it in the reviewed package
- Storage and secrets audit — API tokens or credentials held in extension storage, and how they're protected
- Update and distribution integrity — whether the update channel can be tampered with or spoofed
Mapped to OWASP Top 10:2025
No dedicated "OWASP Top 10" exists for browser extensions — findings map back to Top 10:2025 categories, cross-checked against the manifest permissions model and Manifest V3's remote-code restrictions.
How ComplyArmor runs Chrome extension penetration testing
Manifest and static source review combined with runtime dynamic analysis in a real browser — every permission, messaging, or injection finding is manually verified by actually exploiting the path, not flagged from a linter alone. Delivered as Smart PTaaS — continuous rather than a one-off engagement — and following our testing methodology: discover, scan, exploit, validate. Every finding maps to your compliance requirements.
Frequently asked questions
What is Chrome extension penetration testing?
Static and dynamic security testing of a Chrome or Chromium-based browser extension — auditing manifest permissions, content-script injection into pages, messaging between the extension and the page or background worker, and whether the extension loads remote code at runtime.
Why do browser extensions need their own security testing?
An extension often runs with broader permissions than the web pages it touches — it can read page content, intercept requests, or hold API tokens in its own storage. A single over-privileged permission or an insecure externally_connectable rule can expose every site the extension runs on, not just the extension itself.
Does this cover Manifest V3 extensions?
Yes — testing covers both Manifest V2 and Manifest V3 extensions, including the service-worker background model, declarativeNetRequest rules, and the tighter remote-code restrictions Manifest V3 introduced.
What framework does Chrome extension testing map to?
Findings map back to OWASP Top 10:2025 categories — there's no dedicated OWASP Top 10 for browser extensions — cross-checked against the Chrome Web Store's extension security best practices and the manifest permissions model.