The report is the product. Findings that are not understood are not fixed, and findings that cannot be reproduced are disputed. Most of the value an assessment creates is destroyed or preserved in the write-up.
When to Use
- Writing up a single vulnerability
- Producing a penetration test, code audit, or red team report
- Submitting to a bug bounty program or triaging inbound submissions
- Scoring severity and arguing priority with an engineering team
- Planning coordinated disclosure for an unpatched issue
When NOT to Use
- Finding the bug — use the relevant testing or audit skill first
- Assembling the raw record a report is built from (provenance, artifact
register, evidence, dead ends) — use maintaining-engagement-state; this skill consumes that record
- Incident narratives and postmortems — use
responding-to-incidents - Compliance-framework mapping as the primary goal — different document,
different audience
Anatomy of a Finding
Every finding answers five questions, in this order:
### F-03 Tenant isolation bypass in report export [High]
**Summary**
An authenticated user of any tenant can export reports belonging to other
tenants by supplying an arbitrary report ID to `GET /api/v2/reports/{id}/export`.
**Impact**
Full read access to other customers' report data, including the financial
figures and contact records those reports contain. Any customer account —
including a self-service trial — is sufficient. This is a cross-tenant
confidentiality breach with likely contractual and regulatory consequences.
**Affected**
`api/handlers/reports.go:214` (`handleExport`), deployed in production as of
commit `a1b2c3d`. Reproduced on staging 2026-07-24 14:02 UTC.
**Reproduction**
1. Authenticate as `trial-user@tenant-a` and obtain a session token.
2. Note your own report ID from `GET /api/v2/reports` (e.g. `1041`).
3. Request a neighbouring ID:
curl -H "Authorization: Bearer $TOKEN" \
https://staging.example.com/api/v2/reports/1042/export -o out.csv
4. `out.csv` contains tenant B's data. Confirmed with IDs 1042, 1043, 1055.
**Root cause**
The handler looks the report up by primary key and checks only that the
session is valid. The tenant scope present on the list endpoint
(`WHERE tenant_id = ?`) is absent from the export query.
**Remediation**
Add the tenant predicate to the export lookup, and enforce it at the data
access layer rather than per handler so new endpoints inherit it:
SELECT ... FROM reports WHERE id = ? AND tenant_id = ?
Then audit the remaining 14 handlers that call `findByID` without a scope —
listed in Appendix B.
**References**
CWE-639, OWASP API1:2023 Broken Object Level AuthorizationRules that make findings act-on-able:
- One finding per issue. Bundling ten IDORs into "authorization issues"
guarantees partial fixes.
- Exact locations. File, line, endpoint, commit, and the environment where
you reproduced it.
- Reproduction someone else can run without asking you a question. Include
the setup, the request, and the observed result — not just the payload.
- Root cause, not just symptom. The fix for a symptom leaves the class.
- Remediation that names the change. "Validate input" is not remediation.
- Variants listed. If you found one instance and suspect more, say what you
checked and what you did not.
- Revalidated against what ships. Before a finding goes in the report,
confirm the vulnerable code is not already fixed on a branch you haven't pulled (git log --oneline <checkout>..origin/main -- <file>). One already-patched finding teaches the reader to distrust the rest.
Severity
CVSS is the common currency, but it scores a vulnerability in the abstract. Score with CVSS, then state business impact separately — engineering prioritizes on the second.
CVSS 4.0 base vector example:
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N → 6.9 MediumThen adjust for reality and say why:
| Factor | Raises priority | Lowers priority |
|---|---|---|
| Exposure | Internet-facing, unauthenticated | Internal only, requires admin |
| Data | Regulated, customer, credentials | Synthetic, public |
| Exploit maturity | Public exploit, active exploitation | Theoretical, complex chain |
| Compensating controls | None | WAF rule, network segmentation, monitoring |
| Blast radius | Cross-tenant, whole fleet | Single account, single record |
A Medium CVSS that breaks tenant isolation for a SaaS product is a P1 regardless of the number. Say that explicitly rather than letting the score argue for you. Conversely, do not inflate scores: a report where everything is Critical gets triaged by ignoring it.
Chained findings: report the components individually and report the chain as its own finding with the chain's severity. The chain is what an attacker does; the components are what engineering fixes.
Proof of Concept
Scale the PoC to what proves the point:
- Enough to prove control of the sink.
id=1042returning another tenant's
row proves the bug. Dumping the full database does not prove it harder.
- Non-destructive by default. Do not modify or delete data to demonstrate
write access; write a benign marker to a record you own, or demonstrate the authorization decision without the effect.
- Redact real data. If your evidence contains customer records, redact them
in the report and store the raw evidence separately with access controls.
- State what you did. If you created accounts, uploaded files, or left
artifacts, list them so they can be cleaned up.
For memory-safety and exploitation findings, a crash with a controlled instruction pointer plus an analysis of exploitability is usually the right depth. A weaponized exploit belongs in the report only when the engagement explicitly calls for it.
The Report
1. Executive summary — 1 page, no jargon, answers "how bad and what now"
2. Scope and methodology — what was tested, how, and with what access
3. Coverage and limitations — what was NOT tested, and why
4. Findings — ordered by severity, each self-contained
5. Strategic recommendations— themes across findings, not per-finding fixes
6. Appendices — tooling, raw output, evidence index, retest resultsThe executive summary is written for someone who will read only it. Three things: the overall risk position in a sentence, the two or three findings that matter, and what decision is being asked for. No CVSS vectors, no tool names, no "we ran Nessus."
Coverage and limitations is the section that protects everyone. State the time box, the accounts and environments you had, the components you could not reach, and the testing you were asked not to do. A report silent on limitations implies coverage it did not have, and that silence is what turns a missed bug into a dispute.
Strategic recommendations are where an assessment earns repeat work: the themes. "Authorization is enforced per handler rather than at the data layer; 9 of 14 findings share this root cause." That sentence is worth more than the nine findings.
Writing for the Audience
| Reader | Wants | Give them |
|---|---|---|
| Executive | Risk and decision | One page, plain language, business consequence |
| Engineering manager | Prioritization and effort | Severity, root cause, scope of the fix |
| Engineer | To fix it today | Exact location, reproduction, concrete change |
| Compliance/audit | Evidence and mapping | Methodology, coverage statement, framework refs |
Write the finding for the engineer, and the summary for the executive. Do not average the two into prose that serves neither.
Tone: describe the defect, not the developer. "The export handler omits the tenant predicate" — not "the developer forgot." Reports circulate, and an accusatory report makes the next engagement harder.
Disclosure
For findings in software you do not own:
Day 0 Report privately: security.txt, /security, GitHub advisory, CERT
Day 0-7 Acknowledge receipt; agree a timeline
Day 45 Check in; offer help reproducing
Day 90 Standard public disclosure deadline (adjust for severity and
exploitation in the wild — actively exploited issues warrant faster
public warning; complex fixes may warrant an extension you agree to)- Give a specific deadline at first contact, and honour it.
- Request a CVE when the issue affects released software with other users.
- Do not publish exploit code before a fix is broadly available; describe
impact and mitigation instead.
- If the vendor is unresponsive, escalate to a CERT/CSIRT coordinator rather
than going straight to publication.
- Never test beyond the authorized scope to "improve the report," and never
use a finding as leverage. Both convert a research contribution into a legal problem.
For bug bounty submissions, read the program's scope and rules first, report one issue per submission, and include the impact statement the triager needs to justify the payout internally.
Rationalizations to Reject
- "They'll understand what I mean." They will not, and they will not ask —
they will downgrade it.
- "I'll write it up later." Reproduction details decay within hours.
- "It's obviously Critical." Then it is easy to justify. Justify it.
- "Everything is High so they take it seriously." Inflated severity is how a
report stops being read.
- "I couldn't fully exploit it, so I'll leave it out." Report it with the
evidence you have and state the uncertainty. Silent omission is worse.
- "I found it in the code, so it's still there." You may be reading a stale
checkout. Revalidate against what ships before you file it — a finding fixed three commits ago discredits the whole report.
- "The client won't like the limitations section." They will like it less
after a breach in an area the report implied was covered.
- "No findings means a bad report." A report with honest coverage and no
findings is a valid result. Say what you tested and how deeply.
References
auditing-code-for-vulnerabilities— the audit-side deliverable formatresponding-to-incidents— incident narratives and postmortems- CVSS 4.0 specification; EPSS for exploitation likelihood; CWE for classification
- ISO/IEC 29147 (vulnerability disclosure) and 30111 (handling)