shuvonsec/claude-bug-bounty/bb-methodology

Claude Code and agent skill by shuvonsec/claude-bug-bounty

Trust tier 3
  • community
Source check pending

Checking that the SKILL.md file is still in the repository.

Use at the START of any bug bounty hunting session, when switching targets, or when feeling lost about what to do next. Master orchestrator that combines the 5-phase non-linear hunting workflow with the critical thinking framework (developer psychology, anomaly detection, What-If experiments). Routes to all other skills based on current hunting phase. Also use when asking "what should I do next" or "where am I in the process."

Install

npx vskill@latest install shuvonsec/claude-bug-bounty/bb-methodology

SKILL.md

Bug Bounty Methodology: Workflow + Mindset

Master orchestrator for hunting sessions. Combines the 5-phase non-linear workflow with the critical thinking framework that separates top 1% hunters from the rest.


PART 1: MINDSET (How to Think)

Core Principle

Hunting is not "find a bug" -- it is "prove an attack scenario." Think like an attacker with a specific goal, not a scanner looking for patterns.

Daily Discipline: Define, Select, Execute

Before touching any tool:

  1. Define: "Today I target [feature/domain] to achieve [CIA impact]"
  2. Select: Choose 1-2 vuln classes (IDOR, Race Condition, etc.)
  3. Execute: Focus ONLY on selected techniques. No wandering.
5 Ultimate Goals (Pick One Per Session)
  1. Confidentiality -- steal data the attacker shouldn't see
  2. Integrity -- modify data the attacker shouldn't change
  3. Availability -- disrupt service (app-level DoS only)
  4. Account Takeover -- control another user's account
  5. RCE -- execute commands on the server
4 Thinking Domains
1. Critical Thinking (deep analysis)

Question trust boundaries:

  • Frontend control disabled? Send request directly via proxy
  • user_role=user cookie? Change to admin
  • price=1000 in POST? Change to 1
  • <script> blocked? Try <img onerror=...>

Reverse-engineer developer psychology:

  • Feature A has auth checks -> Similar feature B (newly added) probably doesn't
  • Complex flows (coupon + points + refund) -> Edge cases have bugs
  • /api/v2/user exists -> Does /api/v1/user still work with weaker auth?

What-If experiments:

  • Skip checkout -> hit /checkout/success directly
  • Skip 2FA -> navigate to /dashboard
  • Send coupon request 10x simultaneously -> Race condition?
  • Replace guid=f8a2... with id=100 on sibling endpoint -> IDOR?
2. Multi-Perspective (multiple angles)
PerspectiveWhat to check
Horizontal (same role)User A's token + User B's ID -> IDOR
Vertical (different role)Regular user -> /admin/deleteUser
Data flow (proxy view)Hidden params in JSON: debug=false, discount_rate
Time/StateRace conditions, post-delete session reuse
Client environmentMobile UA -> legacy API with weaker auth
Business impact"What's the $ damage if this breaks?"
3. Tactical Thinking (pattern detection)
  • Naming anomaly: userId everywhere but suddenly user_id -> different dev, weaker security
  • Error diff: Same 403 but different JSON structure -> different backend systems
  • 200 but wrong body length/content: 200 OK with tiny response or "just a moment" text → WAF soft block, not a real response. Run bypass_403.sh to confirm and get baseline diff.
  • Environment diff: Prod vs Dev/Staging -> debug headers, CSP disabled
  • Version diff: JS file before/after update -> new endpoints, removed params
  • Supply chain: Check framework/library versions for known CVEs
  • Third-party integration: Stripe/Auth0/Intercom -> webhook signature missing?
4. Strategic Thinking (big picture)
  • Asymmetry: Defender must patch ALL holes. You only need ONE.
  • Intuition engineering: Log why something "feels wrong." Verify later. Update mental DB.
  • Unknown management: Can't understand something? Add to "investigate later" list. Just-in-Time Learning.
5. AI-Assisted Thinking (model as a second analyst)

Use AI to expand hypotheses, not to declare verdicts. The model is a fast adversarial planner; the browser, proxy, and live requests are the proof layer.

  • Decompose the feature: ask for actors, assets, entry points, state transitions, and trust boundaries.
  • Generate sibling paths: versioned endpoints, mobile routes, legacy APIs, alternate roles, and admin-only variants.
  • Build a role matrix: anonymous, user A, user B, stale session, fresh session, admin, service account.
  • Ask for dev shortcuts: "Where would a tired developer skip a check or reuse a helper?"
  • Ask for chains: "If this bug is real, what bug B and C sit next to it?"
  • Turn ideas into requests: every AI suggestion must become a single reproducible HTTP experiment.
  • Kill weak signals fast: if AI cannot point to a concrete request, response diff, or cross-account delta, the idea stays as a hypothesis.

High-signal prompts:

  • "Given this endpoint and feature, list the 10 most likely trust-boundary mistakes."
  • "What sibling endpoints, methods, or roles should I test next?"
  • "Which bug class would a rushed implementation likely miss here?"
  • "What does the smallest proof request look like?"
  • "What would make this become a real report instead of a scanner hit?"
Amateur vs Pro: 7-Phase Comparison
PhaseAmateurPro
ReconMain domain onlyShadow IT, dev environments, all assets
DiscoveryLook for errorsLook for design contradictions, business logic flaws
ExploitGive up when blockedBuild filter-bypass payloads
EscalationReport the phenomenon onlyChain to real harm (session steal, ATO)
FeasibilityInclude unrealistic conditionsMinimize attack prerequisites
ReportingState facts onlyQuantify business risk
RetestCheck if old PoC failsAnalyze fix method, find incomplete patches
Two Approach Routes
  • Route A (Feature-based): "This feature is complex" -> deep-dive its input handling -> find vuln
  • Route B (Vuln-based): "I want IDOR" -> find endpoints with sequential IDs -> test access control
Anti-Patterns (Stop Doing These)
  • Program hopping: Stick with one target minimum 2 weeks / 30 hours
  • Tool-only hunting: Automation finds duplicates. Manual testing finds unique bugs.
  • Rabbit hole: Max 45 min per parameter. Set a timer. If stuck, sleep on it.
  • No goal: "Just looking around" = wasted time. Always Define first.

PART 2: WORKFLOW (What to Do)

The 5-Phase Non-Linear Flow
+-------------------------------------------------+
| |
| +----------+ +----------+ +----------+ |
| | 1. RECON |---+| 2. MAP |---+| 3. FIND | |
| +----------+ +-----+----+ +-----+-----+ |
| ^ | | |
| | v v |
| | +----------+ +----------+ |
| +----------| 4. PROVE |---+| 5. REPORT| |
| +----------+ +----------+ |
| |
| Non-linear: stuck at any phase -> go back |
| New API found at phase 3 -> return to phase 2 |
| WAF blocks at phase 4 -> origin IP from phase 1 |
+-------------------------------------------------+

THIS IS NOT LINEAR. Move freely between phases. When stuck, return to a previous phase.

Phase 0: SESSION START (Every Time)

Before touching any tool, answer these:

  1. Define: "Today I target [feature/domain] to achieve [C/I/A/ATO/RCE]"
  2. Select: Choose 1-2 vuln classes (IDOR, XSS, SSRF, etc.)
  3. Execute: Focus ONLY on selected techniques
  4. Identity: Anonymous or authenticated? If the bugs you're hunting need a

session (IDOR, BOLA, privilege escalation, auth bypass, mass-assignment), load auth once at session start — see docs/auth-sessions.md. Then every downstream tool (httpx, katana, ffuf, nuclei, dalfox, PoC verifiers) sends those headers automatically and audit log entries are stamped with a stable session_id hash.

Route selection -- Wide or Deep?

SignalWide (recon sweep)Deep (focused testing)
New program, first dayX
Wildcard scope *.target.comX
Main webapp, been here >3 daysX
Scope update (new domain added)X
Found interesting subdomainX
Hunting IDOR / BOLA / auth bugsX (auth-aware)
Phase 1: RECON

Goal: Maximize attack surface. Find what others missed.

Wide approach (initial sweep):

Subdomain enum -> DNS resolution -> HTTP probing -> Port scan -> Tech detect

Deep approach (targeted):

Google Dorks -> JS file download -> Hidden param discovery -> API mapping
What you findNext action
Live subdomains with tech stackPhase 2 (Mapping)
Known software (WordPress, Jira)Check CVEs + defaults immediately
Cloud resources (S3, Firebase)Test permissions (read/write/list)
403 or 200 + block page on endpointbughunter/tools/bypass_403.sh <url> auto-detects soft blocks (200+block-body). Verdict: bypassed/needs_review/blocked. If all blocked after 5 min, skip
Nothing after 5 min on a hostSkip, try next host (5-minute rule)

Command: /recon target.com

After every recon (mandatory):

bash
python3 bughunter/tools/lead_board.py ingest target.com
python3 bughunter/tools/lead_board.py show target.com
python3 bughunter/tools/lead_board.py next target.com
# Route in plain language: "GraphQL endpoint → skills/graphql-audit"
# touch status when you start / kill / report a lead

(hunt.py runs ingest + EOL automatically unless --skip-leads.)

Phase 2: MAPPING & ANALYSIS

Goal: Understand the app like its developer does.

Checklist:

  • [ ] Map all endpoints (Burp/Caido sitemap + JS analysis)
  • [ ] Identify auth model (cookie, JWT, OAuth, SAML?)
  • [ ] Find business-critical flows (payment, registration, password reset, data export)
  • [ ] Download and analyze JS files for hidden routes, secrets, logic
  • [ ] Identify roles and permissions (user, admin, API keys)
  • [ ] Note "weird" behaviors (anomalies in naming, errors, timing)
What you findNext action
JS files with interesting codeTaint analysis (Sink -> Source)
OAuth/SAML authenticationOAuth/SAML checklist
API with ID parametersPhase 3, target IDOR
Complex business logic (payment, coupon)Phase 3, target BizLogic
postMessage listenersDOM analysis, postMessage-tracker
Phase 3: VULNERABILITY DISCOVERY

Goal: Find the bug. Use Error-based first, then Blind-based.

Decision flow based on what you're testing:

What input are you testing?
+-- ID parameter (user_id, order_id)
| -> IDOR checklist
+-- Search/filter/sort field
| -> SQLi, NoSQLi probing
+-- URL input / webhook / PDF gen
| -> SSRF checklist
+-- Text field reflected in page
| -> XSS (DOM or reflected)
+-- File upload
| -> SVG XSS, web shell, path traversal
+-- Price/quantity/coupon
| -> Business logic, race conditions
+-- Login / 2FA / password reset
| -> Auth bypass
+-- Profile update API
| -> Mass Assignment
+-- Template / wiki editor
| -> SSTI
+-- Nothing obvious
-> Fuzz with ffuf, try Error-based probing

Error vs Blind decision:

  1. Try Error-based first (send ', ", {{7*7}}, ${7*7}) -- watch for 500 errors, stack traces
  2. No error? Time-based (SLEEP(10), ; sleep 10;) -- watch response time
  3. No time diff? OOB (curl attacker.com, interactsh) -- watch for DNS callback
  4. Still nothing? Boolean (AND 1=1 vs AND 1=0) -- watch content-length diff
What you findNext action
Low-impact behavior (redirect, self-XSS, cookie injection)Chain it -- find a connector gadget
Confirmed vuln (XSS, IDOR, SQLi)Phase 4 (Prove and Escalate)
Blocked by WAF/CSP/403 or soft-block 200/bypass-403 <url> → check verdict (not just status) → bughunter/tools/waf_encoder.py "<payload>" → if upload: bughunter/tools/multipart_mutator.py → 5 min, kill
Known software vuln (CVE)1-day speed workflow
Nothing after 20 min on this endpointRotate (20-minute rule)
Phase 4: PROVE & ESCALATE

Goal: Prove maximum business impact. Turn Low into Critical.

This is the start of the file. Read the full SKILL.md on GitHub.

Security

  • Security scanPassed, 90 of 100Pattern checks on the skill's files.
  • Model reviewPassed

Quality evaluation

  • Task evaluationNot runNo evaluation yet. Run one in Skill Studio.

Source

Popularity

Repository stars
4,237
Repository forks
768
7-day trend score
42

Stars and forks are for the whole GitHub repository, not this skill alone. Not refreshed yet.

Works with

Any agent vskill installs to: 56 targets in all. These 39 have a page on this site.

  • Claude Code
  • Cursor
  • GitHub Copilot
  • Windsurf
  • Codex
  • Gemini CLI
  • Cline
  • Amp
  • Roo Code
  • Goose
  • Continue
  • Kilo Code
  • Junie
  • Trae
  • OpenHands
  • Qwen Code
  • AI Agent
  • Tabnine Chat
  • Sourcegraph Cody
  • Amazon Q
  • Firebase Genkit
  • Sweep
  • Devin
  • Phind
  • Mentat
  • Claude Desktop
  • Aider
  • GPT Pilot
  • Plandex
  • bolt.new
  • v0
  • Replit Agent
  • Anse
  • TypingMind
  • BetterChatGPT
  • LibreChat
  • Warp AI
  • Pieces
  • Fig AI
Embed badge
vskill VERIFIED badge
[![vskill VERIFIED](https://verified-skill.com/api/v1/skills/shuvonsec/claude-bug-bounty/bb-methodology/badge)](https://verified-skill.com/skills/shuvonsec/claude-bug-bounty/bb-methodology)

Something wrong with this skill or its page? Tell us.