26zl Vendored note (this repo). Adapted from the standalone claude-bug-bounty project. The upstream executable scaffolding — helper scripts (
tools/*.py,tools/*.sh), the standalonewordlists/pipeline, and slash-commands (/recon,/hunt,/validate,/report, …) — is not bundled here: run tooling through the MCP server (run_tool/run_pipeline/run_script) and install via the project installer/registry. Any static deep-dive files this skill needs are vendored into its ownreferences/folder, and cross-skill references resolve by skill name (e.g. thebb-methodologyskill). Some named tools may not be intools_config.jsonyet — add them with theadd-toolskill or install upstream.
TRIAGE & VALIDATION
One wrong answer = STOP. Kill it. Move on.
"N/A hurts your validity ratio. Informative is neutral. Only submit what passes all 7 questions."
THE 7-QUESTION GATE
Ask IN ORDER. One wrong answer = STOP immediately.
Q1: Can an attacker use this RIGHT NOW, step by step?
Complete this template:
1. Setup: I need [own account / another user's ID / no account]
2. Request: [exact HTTP method, URL, headers, body — copy-paste ready]
3. Result: I can [read / modify / delete] [exact data shown in response]
4. Impact: The real-world consequence is [account takeover / PII read / money stolen]
5. Cost: Time: [X minutes], Capital: [$0 / $X subscription required]
If you CANNOT write step 2 as a real HTTP request → KILL IT.
Q2: Is the impact on the program's accepted impact list?
Go to the program page. Find "Vulnerability Types" or "Out of Scope."
Common tiers:
- Critical: Any-user ATO without interaction, RCE, SQLi with data exfil, admin auth bypass
- High: Mass PII exfil, privilege escalation, internal SSRF with data, stored XSS all users
- Medium: IDOR on specific user non-critical data, XSS on sensitive page requiring click
- Low: Non-sensitive info disclosure, clickjacking with PoC
If your bug maps to a listed exclusion → KILL IT.
Q3: Is the root cause in an in-scope asset?
Confirm:
- Vulnerable domain is on the in-scope list (not
*.internal.target.com) - It's a production asset (not staging/dev unless explicitly in scope)
- It's not a third-party service the company just uses (not Stripe, Salesforce, Google Auth)
If out-of-scope → KILL IT.
Q4: Does it require privileged access that an attacker can't realistically get?
- "Admin can do X" = centralization risk = KILL IT (on 99% of programs)
- "Non-admin can do X that only admin should do" = valid
- "Requires physical access / MFA device" = usually invalid
- "Requires compromised victim account to work" = questionable, low severity at best
Q5: Is this already known or accepted behavior?
Search:
- Program's HackerOne/Bugcrowd disclosed reports: Ctrl+F endpoint name + bug class
- GitHub issues on target repo:
is:issue label:security ENDPOINT_NAME - Changelog/CHANGELOG.md — does it mention this behavior?
- API docs / design docs — is it documented as intended?
If acknowledged/design decision → KILL IT.
Q6: Can you prove impact beyond "technically possible"?
- XSS → show actual cookie theft or session hijack, not just
alert(1)oralert(document.domain) - SSRF → hit an internal endpoint that returns data, not just DNS ping
- SQLi → show actual data exfil from a real table, not just error message
- IDOR → show actual other-user's data in response, not just a 200 status code
If you can only show "technically possible" → DOWNGRADE severity, not kill.
Q7: Is this a known-invalid bug class?
Check the NEVER SUBMIT list below. If it's on this list without a chain → KILL IT.
Q8: Identity check — which session found this, and does it survive?
For any finding made under an authenticated hunt, record the answer to each:
1. Session ID: [12-char BBHUNT_SESSION_ID hash from audit.jsonl]
2. Identity: [low-priv user A / high-priv user B / API key / etc.]
3. Anonymous repro: Does the same request work with NO auth header?
4. Cross-identity: Does it work under session B with the same data scope?
5. Stale-cred repro: Does a logged-out / expired session still get the data?
Why this matters:
- IDOR / BOLA: must work with session A reading session B's data — if it only works with no auth, that's "missing auth" not IDOR (different bug, different severity).
- Priv-esc: must work with low-priv session reading high-priv data — if both sessions can already see it, no bug.
- Auth bypass: must work without a valid session — if it stops working when you log out, you've found a permissions issue, not a bypass.
- Always check both directions: a finding that only reproduces under one identity is often a real, scoped permission boundary, not a vuln.
audit.jsonl entries are tagged with session_id. Re-run the request
under each identity and confirm the bug holds before writing the report.
This is the most common reason "confirmed IDOR" findings come back as N/A.
If you cannot answer the identity questions, treat the finding as unproven. Blank answers auto-fail on auth-related findings.
4 PRE-SUBMISSION GATES
Run in sequence. ALL 4 must PASS.
Gate 0: Reality Check (30 seconds)
[ ] Bug is REAL — confirmed with actual HTTP requests, not code reading alone
[ ] Bug is IN SCOPE — checked program scope page explicitly
[ ] Reproducible from scratch — can reproduce starting from fresh session
[ ] Evidence ready — screenshot, response body, or video
Gate 1: Impact Validation (2 minutes)
[ ] Can answer: "What can attacker DO that they couldn't before?"
[ ] Answer is more than "see non-sensitive data" (unless program pays for info disclosure)
[ ] Real victim: another user's data, company's data, financial loss
[ ] Not relying on victim doing something unlikely
Gate 2: Deduplication Check (5 minutes)
[ ] Searched HackerOne Hacktivity for this program + similar bug title/endpoint
[ ] Searched GitHub issues for target repo
[ ] Read most recent 5 disclosed reports for this program
[ ] Not a "known issue" in their changelog or public docs
[ ] Google: "TARGET_NAME ENDPOINT_NAME bug bounty"
Gate 3: Report Quality (10 minutes)
[ ] Title: [Bug Class] in [Endpoint] allows [actor] to [impact]
[ ] Steps to Reproduce: copy-pasteable HTTP request
[ ] Evidence: screenshot/video of actual impact (not just 200 status)
[ ] Severity: matches CVSS 3.1 score AND program's severity definitions
[ ] Remediation: 1-2 sentences of concrete fix
[ ] NEVER used "could potentially" or "may allow"
NEVER SUBMIT LIST
Submitting these destroys your validity ratio.
Missing CSP / HSTS / security headers
Missing SPF / DKIM / DMARC
GraphQL introspection alone (no auth bypass, no IDOR demonstrated)
Banner / version disclosure without working CVE exploit
Clickjacking on non-sensitive pages (no sensitive action PoC)
Tabnabbing
CSV injection (no actual code execution shown)
CORS wildcard (*) without credential exfil proof of concept
Logout CSRF
Self-XSS (only exploits own account)
Open redirect alone (no ATO or OAuth theft chain)
OAuth client_secret in mobile app (known, expected)
SSRF DNS callback only (no internal service access or data)
Host header injection alone (no password reset poisoning PoC)
Rate limit on non-critical forms (search, contact, login with Cloudflare)
Session not invalidated on logout
Concurrent sessions
Internal IP in error message
Mixed content
SSL weak ciphers
Missing HttpOnly / Secure cookie flags alone
Broken external links
Autocomplete on password fields
Pre-account takeover (usually — very specific conditions required)
COMMON N/A CLASSES — KILL SIGNALS
These pass basic gut-check but consistently come back N/A. Each row has a specific signal that tells you to kill it before writing the report.
| Finding | Why it N/As | Kill signal — if you see this, stop |
|---|---|---|
| Reflected XSS | CSP blocks execution; sandbox context; no session access | Dalfox found alert(1) but no cookie in response; Content-Security-Policy header present |
| SSRF — DNS callback only | No internal data reached; programs require HTTP response with data | Interactsh/Collaborator got DNS ping but no HTTP reply with internal content |
| IDOR — own data only | Attacker == victim; no cross-account access proven | User ID in response matches your own test account |
| SQLi — error message only | WAF filtered or error is cosmetic; no data exfiltrated | Got DB error string but no actual table rows returned |
CORS wildcard * |
* blocks withCredentials; no PII actually exfiltrated |
Access-Control-Allow-Credentials: true absent; credentialed request returns 403 |
| Rate limit missing — non-sensitive endpoint | Program only pays for rate-limit on auth/payment/OTP surfaces | Endpoint handles search, contact form, or sits behind Cloudflare |
Nuclei info template match |
Version detection, not exploitation | Template severity is info; no CVE PoC executed against live service |
| MFA rate limit (no lockout) | Impact depends on OTP brute-force succeeding — it usually doesn't | 15 requests returned 200 but no OTP code was accepted |
| Open redirect alone | Redirect is informational without token theft chain | No OAuth redirect_uri parameter; no auth code or token in the redirected URL |
| Auth bypass — admin precondition | Requires compromised admin to trigger; attacker can't get there | "Admin can do X on behalf of user" — attacker must already be admin |
XSS via alert(document.domain) |
Not proof of session theft | PoC shows domain popup only; no document.cookie exfil, no event listener |
| SAML metadata exposed | Disclosure only — aids attack but is not standalone impact | No private key or signing cert extracted; metadata is publicly documented by IdP |
Decision rule: if your finding matches a kill signal → classify as [INFORMATIONAL], do not run the 7-Question Gate, move on.
CONDITIONALLY VALID — CHAIN REQUIRED
Build the chain first, prove it works end to end, THEN report.
| Standalone Finding | Chain Required | Valid Result |
|---|---|---|
| Open redirect | + OAuth redirect_uri → auth code theft | ATO (Critical) |
| Clickjacking | + sensitive action + working PoC | Medium |
| CORS wildcard | + credentialed request exfils user PII | High |
| CSRF | + sensitive action (transfer funds, change email, delete account) | High |
| Rate limit bypass | + OTP/reset token brute force succeeds | Medium/High |
| SSRF DNS-only | + internal service access + data returned | Medium |
| Host header injection | + password reset email uses injected host | High |
| Prompt injection | + reads other user's data (IDOR) | High |
| S3 bucket listing | + JS bundles contain API keys or OAuth secrets | Medium/High |
| Self-XSS | + CSRF to trigger it on victim without their knowledge | Medium |
| Subdomain takeover | + OAuth redirect_uri registered at that subdomain | Critical |
| GraphQL introspection | + auth bypass mutation or IDOR on node() | High |
CVSS 3.1 QUICK REFERENCE
Common Score Examples
| Finding | Score | Severity | Vector |
|---|---|---|---|
| IDOR read PII, any user, auth required | 6.5 | Medium | AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| IDOR write/delete, any user | 7.5 | High | AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| Auth bypass → admin panel | 9.8 | Critical | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Stored XSS → cookie theft, stored | 8.8 | High | AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N |
| SQLi → full DB dump | 8.6 | High | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| SSRF → cloud metadata | 9.1 | Critical | AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N |
| Race → double spend | 7.5 | High | AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N |
| GraphQL auth bypass | 8.7 | High | AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| JWT none algorithm | 9.1 | Critical | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Metric Quick Guide
| What you have | Metric | Value |
|---|---|---|
| Exploitable over internet | AV | Network (N) |
| No special timing or race | AC | Low (L) |
| Free account needed | PR | Low (L) |
| No login needed | PR | None (N) |
| Admin needed | PR | High (H) |
| No victim action | UI | None (N) |
| Victim must click | UI | Required (R) |
| Reads all data | C | High (H) |
| Reads some data | C | Low (L) |
| Modifies all data | I | High (H) |
| Crashes service | A | High (H) |
| Affects only app | S | Unchanged (U) |
| Affects browser/OS/cloud | S | Changed (C) |
KILL FAST RULES
The goal is to QUICKLY disqualify bad leads so you hunt real bugs:
- 5-minute rule: If you can't fill in Q1's template in 5 minutes → move on
- Precondition count: More than 2 preconditions simultaneously required → kill it
- Impact test: "What does attacker walk away with?" — if nothing tangible → kill it
- Admin bypass: "Admin can do X" is NEVER a bug → kill it immediately
- Design doc test: If it's documented behavior → kill it immediately
- Rabbit hole signal: 30+ min on Q6 with no reproducible PoC → kill it
ANTI-PATTERNS THAT LOSE MONEY
Writing a report before confirming the bug exists (most common)
Submitting theoretical impact without proof
"The API returns more fields than necessary" (sensitivity matters — is it actually sensitive?)
Chaining A+B into one report when they're separate bugs (two separate payouts)
Reporting B saying "similar to A in my other report" — fresh Gate 0 for every bug
Overclaiming severity — triagers trust you less next time
Under-describing impact — triager doesn't understand why it matters