Challenges

Make a page run your code in someone else's browser.

Abuse XML parsers to read files and reach internal systems.

Test real application routes for missing object, role, and tenant authorization checks.

Observe how real browser cookie attributes change XSS and cross-site request behavior.

Test whether sensitive interfaces can be framed and visually disguised by another site.

Find sensitive details leaked through errors, forgotten files, metadata, and deployment artifacts.

Modify fields the frontend never intended users to control and see whether the backend binds them anyway.

Abuse legitimate server-side URL fetchers to reach destinations users cannot access directly.

Make a signed-in browser perform state-changing actions from an unrelated website.

Find server features that build operating-system commands from user-controlled values and test common filter bypasses.