Cookie on the Wire
A02 · ≈ 20 min · 0 solves
Explore the application as a real target: map the exposed functionality, inspect requests and responses, build a working exploit, and recover the rotating flag. If you get stuck, the verified official solution is available below as an optional spoiler.
Rules of engagement
Stay inside the generated lab URL. Use only the synthetic accounts and data in this instance. The main SecOne4all site and external systems are out of scope.
Challenge brief
What counts as a valid solve
Recover session data made unsafe by incorrect cookie scope and transport attributes.
GET /session/start.
prove that the deployed configuration exposes the protected synthetic value or privileged operation; the successful workflow returns the current rotating flag.
Work only inside your generated lab URL and submit the flag within 20 minutes.
Official solution
Contains the complete exploitation path. Open it only when you want the spoiler.
Reveal official solutionStep-by-step · verified against the live lab
Official solution · A02 · Cookie on the Wire
Objective
Recover session data made unsafe by incorrect cookie scope and transport attributes.
Steps
- Start the isolated lab and inspect the root page for the intended diagnostic or configuration surface.
- Enumerate only the synthetic endpoint named by the scenario; no external target is required.
- Send: GET /session/start and inspect the response body and Set-Cookie attributes
- Confirm the response exposes the misconfiguration and contains the rotating
flagfield (or embeds it in the returned synthetic artifact). - Submit the flag on the SecOne4all challenge page.
Expected proof
A successful response for cookie-security-attributes returns the instance-specific rotating flag. The flag is valid only for the current player and running instance.
Safety boundary
Use only the generated lab URL. No request to the main site, another user, or an external service is part of this solution.