How to Audit Chrome Extensions for Security Risk
Browser extensions are one of the most under-managed attack surfaces in most organisations. An extension can request permission to read and change everything on every website you visit, run in the context of your authenticated sessions, and update itself silently — so a benign extension can become malicious after an update or an ownership change. Auditing Chrome extensions for security risk means inventorying what is installed across the fleet, reviewing the permissions each one requests against what it actually needs, checking publisher reputation and update history, and enforcing a policy (allowlist, block, or review) through browser management. This guide covers the risk model and a practical audit process.
Browser extensions sit in a blind spot: they run inside your authenticated sessions, can often read and change every page you visit, and update themselves silently — yet most organisations have no inventory of what employees have installed. That combination of broad access and silent change makes extensions a real attack surface, and a periodic audit is how you keep it in check.
The risk model
An extension with "read and change all your data on all websites" permission can see and manipulate anything in your browser, including data inside apps you are logged into. Because extensions auto-update, a safe extension can turn malicious after an update or after its developer sells it — a repeatedly-seen supply-chain pattern. Broad access + silent change = the core risk.
The audit process
- Inventory. Enumerate installed extensions across the fleet via browser management or endpoint tooling — you cannot manage what you cannot see.
- Review permissions vs purpose. For each extension, compare requested permissions to what its function actually needs. A calculator that wants to read every website is a red flag.
- Check reputation and updates. Publisher reputation, user base, and update/ownership history — extensions that changed hands deserve scrutiny.
- Flag and decide. Excessive permissions, poor reputation or unclear ownership → block or review.
Enforce a policy at scale
Use browser enterprise management (Chrome policies) to allowlist approved extensions, block the rest, prevent silent installs, and control permissions — then re-audit periodically so newly-risky extensions are caught after updates.
Scan a specific extension with the free Extension Scanner →.
Frequently asked questions
Why are extensions risky? Broad access to your sessions plus silent auto-updates — a safe extension can turn malicious after an update or sale.
How do I audit them? Inventory the fleet, review permissions vs purpose, check reputation/updates, flag and decide.
Which permissions concern? "Read/change all data on all sites", history, cookies, managing other extensions — when they exceed purpose.
Control at scale? Browser enterprise policies: allowlist, block, prevent silent installs, re-audit.
Ready to practise the decisions these articles describe?
Run a free War Room →