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+# M015 Cross-User Authorization Replay Report
+
+This report covers the follow-up tenant-boundary work after `M013` and `M014`.
+
+Related artifacts:
+
+- `docs/security-assessments/M013-adversarial-security-assessment.md`
+- `docs/security-assessments/M014-security-remediation-verification.md`
+- `docs/security-assessments/M015-hostile-fixture-setup.md`
+- `docs/security-assessments/M015-hostile-fixture-setup.json`
+- `docs/security-assessments/M015-s02-probe-results.json`
+
+## Test Setup
+
+A dedicated hostile-test SQLite database was created from the current EF model because the default development DB was missing core domain tables needed for real authorization probes.
+
+Fixture runtime:
+
+- clean SQLite DB under `.tmp/m015-fixture`
+- API started with `Data__Root=/home/pi/development/JobTracker/.tmp/m015-fixture`
+- registration temporarily enabled for the fixture runtime
+- two real local users created through the API:
+  - `alice.m015@example.com`
+  - `bob.m015@example.com`
+
+Alice-owned fixture resources created through the real API:
+
+- `company_id = 1`
+- `job_id = 1`
+- `correspondence_id = 1`
+- `attachment_id = 1`
+
+All mutating requests used the real cookie + CSRF contract.
+
+## Cross-User Probe Summary
+
+Bob targeted Alice’s fixture ids with a real authenticated session.
+
+### Defended in this pass
+
+The following probes failed closed with `404` when Bob targeted Alice’s resources:
+
+- `GET /api/attachments/1`
+- `GET /api/attachments/download/1`
+- `PATCH /api/attachments/1`
+- `DELETE /api/attachments/1`
+- `GET /api/correspondence/1`
+- `DELETE /api/correspondence/1`
+- `GET /api/jobapplications/1`
+- `PUT /api/jobapplications/1`
+- `PATCH /api/jobapplications/1/followup`
+- `GET /api/jobapplications/1/timeline`
+- `GET /api/jobapplications/1/tailored-cv-draft`
+- `GET /api/jobapplications/1/followup-draft`
+
+These routes did not expose or mutate Alice-owned data in this hostile fixture pass.
+
+## Confirmed Finding
+
+### Cross-user read leak on job history
+
+- **Category:** Authorization / data exposure
+- **Endpoint:** `GET /api/jobapplications/{id}/history`
+- **Risk:** **Medium**
+
+#### Vulnerability
+
+Before the fix, Bob could request Alice’s job history by raw job id and receive Alice’s `JobEvent` rows.
+
+Observed pre-fix response:
+
+- `GET /api/jobapplications/1/history` as Bob
+- `200 OK`
+- payload included Alice-owned event data, including the `Created` event for Alice’s job
+
+#### Example exploit input
+
+```http
+GET /api/jobapplications/1/history
+Cookie: jobtracker_auth=<bob session cookie>
+```
+
+#### Root cause
+
+Two issues combined:
+
+1. `GetHistory(...)` queried `JobEvents` directly by `JobApplicationId` without verifying that the parent job belonged to the current user.
+2. `JobEvent` had no owner-scoped query filter in `Data/JobTrackerContext.cs`.
+
+#### Fix
+
+- `GetHistory(...)` now checks whether the requested job exists in the current user’s scoped `JobApplications` query and returns `404` if it does not.
+- `JobEvent` now has an owner-scoped query filter tied to `JobApplication.OwnerUserId`.
+- Added focused regression test:
+  - `JobTrackerApi.Tests/JobApplicationsAuthorizationTests.cs`
+
+#### Replay after fix
+
+Observed post-fix response:
+
+- `GET /api/jobapplications/1/history` as Bob
+- `404 Not Found`
+
+#### Verdict
+
+**Fixed.**
+
+## Automated Evidence
+
+### Focused regression test
+
+```bash
+dotnet test JobTrackerApi.Tests/JobTrackerApi.Tests.csproj --filter JobApplicationsAuthorizationTests
+```
+
+Observed:
+
+- passed
+- verifies `GetHistory` returns `NotFound` for another user’s job
+
+## Final Assessment
+
+For the prioritized raw-id authorization seams exercised in this milestone:
+
+- **confirmed and fixed:** `GET /api/jobapplications/{id}/history`
+- **no finding in this fixture pass:** attachments, correspondence, primary job read/update, follow-up patch, timeline, tailored draft, follow-up draft
+
+## Remaining Boundary
+
+This report covers the endpoints actually exercised in the hostile fixture pass. It does **not** claim that every authorization-sensitive route in the application has been exhaustively proven safe; it closes the high-risk raw-id seams prioritized from the earlier assessment with a real two-user runtime and replay evidence.