Application Data Exposure Testing
Distinguish real unauthorized data exposure from harmless metadata - response field...
Install
npx skills add xalgorix/xalgorix --skill application-data-exposure-testing -g -a claude-code -y- Repository
- xalgorix/xalgorix1.3k
- Category
- Engineering
- Updated
- 6d ago
- License
- Apache-2.0
- Context cost
- Mediumabout 1,811 tokens
- Runs scripts
- No, instructions only
What it does
Distinguish real unauthorized data exposure from harmless metadata - response field differentials by role and tenant, over-fetching, alternate serializers and exports, error responses, notifications, audit logs, cached content - requiring meaningful confidentiality or authorization impact to report.
Application Data Exposure Testing
Purpose
Applications leak data through many channels beyond "the endpoint returned a field": nested objects, alternate serializers, exports, error responses, notifications, audit logs, caches. Most such leakage is harmless metadata. This skill finds the subset with meaningful confidentiality or authorization impact - by asking, for every response, what THIS identity should have received versus what it actually received.
Entry Conditions
- You can observe the same application object or operation from at least two identity contexts (roles, tenants, or anonymous)
- OR: the application has export/report/serialization surfaces beyond the primary API
Differential Reasoning (the core method)
For every response channel:
what should THIS identity receive for this object?
vs
what did it actually receive?
Concretely: fetch the same object as the legitimate owner, then as a different identity (authz_matrix automates the replay), and DIFF the payloads field by field. Fields present in the attacker-context response that belong to another principal are exposure. Fields that are merely descriptive of your own data are not.
