Vendor Binary
A03 · ≈ 50 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
Identify a concealed behavior in a precompiled helper shipped inside the repository.
GET /vendor?arg={value}.
prove that the untrusted synthetic component reaches the build, registry, or release workflow; the successful workflow returns the current rotating flag.
Work only inside your generated lab URL and submit the flag within 50 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 · A03 · Vendor Binary
Objective
Identify a concealed behavior in a precompiled helper shipped inside the repository.
Steps
- Start the isolated ForgeWorks workspace and open its build, registry, package, or update operation.
- Run the normal resolution or promotion once and note the expected trusted input.
- Manipulate the live supply-chain operation: GET
/vendor?arg=--diagnostic. - Confirm the untrusted component reaches the build or release and returns the rotating flag.
- Submit the flag before stopping the lab.
Expected proof
A successful response for vendored-binary-backdoor 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.