Hunt Exceptional Conditions
Hunt mishandling of exceptional conditions, feed an endpoint malformed/unexpected...
Install
npx skills add elementalsouls/Claude-BugHunter --skill hunt-exceptional-conditions -g -a claude-code -y- Repository
- elementalsouls/Claude-BugHunter5.4k
- Category
- Engineering
- Updated
- 3d ago
- License
- MIT
- Context cost
- Lightabout 643 tokens
- Runs scripts
- No, instructions only
What it does
Hunt mishandling of exceptional conditions, feed an endpoint malformed/unexpected input (wrong type, broken JSON, oversized field, null byte) and make it fail OPEN or leak internals: a verbose stack-trace / framework error page that discloses ORM internals, server file paths, library versions, or a language traceback. Use on any input-accepting endpoint (JSON APIs, forms, query params). Medium-High when the leak exposes internal structure that arms a deeper attack.
HUNT-EXCEPTIONAL-CONDITIONS, Verbose Errors / Fail-Open (A10:2025)
What actually pays
Well-built apps catch errors and return a clean, generic message. A broken app, when handed input it didn't expect, throws an unhandled exception and renders a developer error page straight to the client, leaking the stack trace, the ORM/query internals, server-side file paths, and framework/library versions. That disclosure is the finding (and it arms SQLi/RCE/path attacks next).
Recon
Any endpoint that parses input is a candidate; the richest are:
JSON APIs that expect typed fields: POST /api/* with {numbers, ids, enums}
Endpoints with numeric/id path or query params: /item/{id}, ?page=, ?quantity=
Search / filter / sort params
File or content-type sensitive uploads
Attack, send what the code didn't anticipate
Take a known-good request and break ONE assumption at a time:
- Wrong type: a field the app expects to be a number/string is sent as an
array or object,
{"rating":"x","comment":[1,2,3]},{"quantity":{}}. - Malformed body: truncated/!invalid JSON, an unterminated string, a stray brace, a wrong/missing Content-Type.
- Boundary/oversized: a very long string, a huge/negative/overflow number.
- Null byte / control chars embedded in a value.
POST /api/Feedbacks {"rating":"notanumber","comment":[1,2,3]}
GET /item/' OR /item/%00 (also exercises the error path)
Watch the RESPONSE BODY, not just the status: a 500 (or even a 200/400) whose body contains a stack trace or framework error page is the signal.
What counts as a leak (the success signal)
A finding is confirmed when the response body contains a cross-framework error-disclosure signature:
