Auth & Client-Side Security
low Severity
Free Check
Cross-Tab Opener Leakage (rel="noopener")
Ensures external links with target="_blank" declare rel="noopener noreferrer" to prevent reverse tab-nabbing.
Why It Matters
Without noopener, the opened tab has window.opener access and can navigate your tab to a fraudulent login page.
How We Check This
We scan all <a> tags with target="_blank" and flag any missing rel="noopener" or rel="noreferrer".
How to Fix & Implement
Copy-paste configuration blocks tailored for your web server or edge proxy.
nginx snippet
<a href="https://external.com" target="_blank" rel="noopener noreferrer">Link</a>
Frequently Asked Questions
What is reverse tab-nabbing?
An attack where a newly opened link redirects the parent tab using window.opener.location = "https://phishing.com".