# Sensitive data in errors, debug routes, or generated files

An error or debug output crosses a confidentiality boundary by revealing protected state.

**Candidate CWE:** [CWE-209](https://cwe.mitre.org/data/definitions/209.html)

## Test hypothesis

Send one malformed request for a synthetic object and compare it with the successful request. Identify a private marker, secret-bearing configuration, or privileged internal artifact in the response. If access is through a backup or debug file instead of an error message, map that actual exposure cause.

## Evidence required

Retain the exact request, redacted output, marker ownership, and intended confidentiality rule. Explain how the disclosed value enables the claimed impact without gathering unrelated records.

## Rule out false positives

A generic stack trace, version banner, local path, or public schema can be only informational; it does not automatically prove sensitive-data exposure or code execution.

## Playbook and command references

- [Source review: entry point to protected operation](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/modules/source-dataflow.html) — Trace attacker control and authorization through handlers, services, queues, and sensitive operations; promote only reachable violations of a stated invariant.
- [Uploads, downloads, paths, archives, and XML](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/modules/file-boundaries.html) — Follow a file through acceptance, storage, processing, publication, and retrieval while preserving ownership and path boundaries.

[Find the associated command snippets](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/commands.html?q=Source%20review%3A%20entry%20point%20to%20protected%20operation)

## Referenced by these target playbooks

[Web & API](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/web-api.html) · [OSS & self-hosted](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/oss.html) · [AI, agents & MCP](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/ai.html)

## Report checklist

- [ ] Capture the affected version, configuration, identities, and object ownership.
- [ ] Preserve a valid baseline and a negative control.
- [ ] Reproduce the forbidden data access, action, or state change on controlled fixtures.
- [ ] Explain the intended security rule and why the observed behavior violates it.
- [ ] State prerequisites, uncertainty, cleanup, and the smallest demonstrated impact.

## Conditional ATT&CK mapping

No direct ATT&CK mapping selected. Record the weakness and demonstrated impact without forcing an adversary-behavior classification. See the [mapping guide](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/attack.html).

## Primary references

- [PortSwigger information disclosure](https://portswigger.net/web-security/information-disclosure)

[Back to the complete vulnerability catalog](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/vulnerabilities.html)