Hintru Tip ENES ← All labs

Breach - WebVerse (GraphQL)

EN easy CTF challenge GraphQLIntrospectionBroken Access ControlInformation DisclosureAPI Security
Original

The Breach challenge on WebVerse Labs exposes a GraphQL API backing a notes application. The notes are visible in the UI, but a GraphQL schema often has surfaces the front-end never touches. Map what's really there, and find a way to reach the flag.

0/4
solved
Step 1 Step 2 Step 3 Step 4
loot

Step 4 · Pass an Argument to Reach the Restricted Field

Objective: Pass `debug:true` as an argument to the `flag` field and retrieve the flag value along with its other fields.

Context: Querying `flag { value }` without arguments results in an error. Introspection revealed that the `flag` field accepts a `debug` boolean argument — similar to how `notes` accepts `includePrivate`. The naming strongly implies that setting `debug: true` may unlock access to the flag value.

Progressive hints

Only reveal the ones you need. Claude tracks how many you used to calibrate the feedback.

Hint 1 — directional nudge

You already know that GraphQL fields can take arguments in parentheses. Think about what argument the `flag` field accepts and what value might unlock it.

Hint 2 — technique / vuln class

The `flag` field accepts a `debug` boolean argument, just like `notes` accepts `includePrivate`. Try passing `debug:true` to the flag query the same way `includePrivate:false` was passed to notes.

Hint 3 — near solution

Send this query:
```json
{"query":"{ flag(debug:true) { id value accessLevel } }"}
```
This should bypass the access restriction and return the flag.

Ask the tutor

Chat with a spoiler-safe tutor for this step. It uses only this lab spec and gives the smallest useful nudge first.

Tell the tutor what you tried, where you got stuck, or paste the response/error you are seeing.

Your attempt

Spotted something to improve?

Polish the wording, sharpen a hint, add missing context, fix a payload — your version stays separate from the original and other learners can choose it.

⚠ Report this lab

Enjoying Hintru? Buy me a coffee ☕ ☕