hunt-captcha-bypass
Hunt CAPTCHA Bypass — 6 distinct patterns: (1) CAPTCHA field simply omitted from the request (server-side validation absent), (2) CAPTCHA token replayed from a solved challenge (no single-use enforcement), (3) CAPTCHA response accepted on a different endpoint than it was solved on (no binding to action/session), (4) static or predictable CAPTCHA values accepted (e.g. '0', 'null', empty string), (5) audio/accessibility CAPTCHA trivially solvable programmatically, (6) CAPTCHA only enforced after N failures (first N requests bypass it). Detection: intercept a successful form submission, remove the CAPTCHA field entirely, replay — if it still succeeds, server-side validation is absent. Medium severity standalone; High when it removes the only rate-limit gate protecting a login, registration, or payment endpoint.
git clone --depth 1 https://github.com/elementalsouls/Claude-BugHunter /tmp/hunt-captcha-bypass && cp -r /tmp/hunt-captcha-bypass/skills/hunt-captcha-bypass ~/.claude/skills/hunt-captcha-bypassSKILL.md
## Autonomous Testing Priority **The fastest test: just omit the CAPTCHA field entirely. Most CAPTCHA bypass bugs are client-side-only validation.** **Pattern 1 — Omit the CAPTCHA field (most common, most automatable):** 1. GET the form/endpoint that shows a CAPTCHA to understand its field name (usually `g-recaptcha-response`, `captcha`, `captcha_token`, `captcha_answer`, `h-captcha-response`) 2. POST the form with ALL fields EXCEPT the CAPTCHA field 3. If the action succeeds (200, redirect, or "success" message) → no server-side CAPTCHA validation 4. Proof: the state-changing action completes without a valid CAPTCHA field (compare against a baseline request that includes it) **Pattern 2 — Empty or null CAPTCHA value:** Instead of omitting the field entirely, include it with an empty string, `null`, `0`, or `undefined`: ``` captcha=&email=test@example.com&password=test123 ``` Some apps validate field presence but not content. **Pattern 3 — Replay a previously solved CAPTCHA token:** 1. Complete one legitimate CAPTCHA challenge and capture the `g-recaptcha-response` token 2. Submit a second request immediately with the SAME token value 3. If the second submission also succeeds → token is not single-use (replay attack) 4. A replayed token can be shared across automated requests **Pattern 4 — Test without CAPTCHA on similar endpoints:** Some apps add CAPTCHA to the registration form but forget the password reset, API endpoint, or mobile API path (`/api/register` vs `/register`). Try the same action via the API path without any CAPTCHA field. **Pattern 5 — Rate/throughput-gated "prove you're automated" challenges:** Some apps define CAPTCHA "bypass" as simply exceeding the rate a human could plausibly sustain — e.g. "N submissions within T seconds" — checked by a middleware that counts REQUESTS REACHING the route, not successful outcomes. Garbage/placeholder payloads satisfy this exactly as well as valid ones, since the counter increments regardless of whether the request's own validation passes. **Timing note (sliding-window counters):** don't solve this one request at a time — a sequential pace (seconds between each request) structurally cannot land N requests inside a short sliding window, and issuing more requests serially does not fix it. A typical failing pattern is 12 requests spread across ~250 seconds when the check requires ~10 requests within 20 seconds. Instead fire the requests **concurrently** (e.g. `"concurrency": N` on a single request call, or any parallel-request primitive your tooling offers, with N >= the required count) so they arrive simultaneously and satisfy the sliding window trivially. Check the endpoint's own required-field validation first (e.g. a `rating` field that can't be null) so the concurrent payload is at least well-formed enough to reach the counting middleware, even if other fields (like the CAPTCHA answer itself) are wrong or reused. **What to skip in automated testing:** Solving real reCAPTCHA/hCaptcha programmatically (OCR, audio bypass) requires external services. Only attempt if patterns 1-4 fail and the test budget allows. **Proof:** Any successful state-changing action (account created, login succeeded, form submitted) that completed without a valid CAPTCHA token confirms the bypass. --- ## Vulnerability Classes in This Skill ### 1. Client-Side-Only CAPTCHA Validation JavaScript hides/disables the submit button until CAPTCHA is solved, but the server never checks the CAPTCHA token. Direct API calls bypass the UI gate entirely. ### 2. CAPTCHA Not Tied to Session or Action A token solved for login is accepted on the registration endpoint (or any other). The server validates "is this a real CAPTCHA solution?" but not "is this the right solution for THIS action?". ### 3. Single-Use Not Enforced CAPTCHA tokens (especially reCAPTCHA v2) are meant to be consumed after one use. If the server doesn't revoke them after verification, a single human-solved token becomes reusable for many requests. ### 4. CAPTCHA Added Reactively (Only After N Failures) Some apps only show CAPTCHA after 3-5 failed login attempts. Before that threshold, no CAPTCHA is required → an attacker can make N-1 attempts per account indefinitely by resetting state between attempts. ### 5. Static or Predictable CAPTCHA Math CAPTCHAs (`3 + 4 = ?`), simple image CAPTCHAs, or text CAPTCHAs with a finite answer set can be automated. These are custom CAPTCHA implementations, not Google/hCaptcha. --- ## Impact Chain CAPTCHA bypass alone: **Medium** (enables automation of rate-limited actions) CAPTCHA bypass + login endpoint = **brute force gate removed** → chain with `hunt-brute-force` → High/Critical CAPTCHA bypass + registration endpoint = **account farming** → abuse, spam, resource exhaustion CAPTCHA bypass + password reset = **token flooding** → chain with `hunt-forgot-password` --- ## Related Skills - **`hunt-brute-force`** — CAPTCHA is often the only rate-limit gate; bypass unlocks brute force - **`hunt-forgot-password`** — reset endpoints sometimes protected by CAPTCHA only - **`hunt-race-condition`** — race the CAPTCHA validation window (submit before the token is revoked)
End-to-end Android APK red-team pipeline — automated APK acquisition (Play Store + apkpure + apkmirror fallback), jadx decompilation, secret/URL/JWT/Firebase grep, pinned-cert extraction, exported-component enumeration, Frida runtime instrumentation templates, intent-injection probes. Built from an authorized external red-team engagement where 7 APKs were pulled manually, 4 download attempts truncated, and a hardcoded JWT + 30 internal API endpoints were recovered from one of the apps. Use when target has a mobile app catalogue (Play Store developer page), when you find an APK URL hosted on a web server, or when post-recon mentions "mobile app" in scope.
Run autonomous hunt loop on a target — scope check → recon → rank surface → hunt → validate → report with configurable checkpoints. Usage: /autopilot target.com [--paranoid|--normal|--yolo]
Local-tooling companion to the bug-bounty orchestrator — carries the SAME complete bug-bounty workflow, but reach for THIS variant when you also need to resolve where tools, wordlists, and clones are installed on the local machine (jhaddix, SecLists, trufflehog, ffuf, dalfox, ghauri); for pure orchestration/routing use the bug-bounty skill. Workflow it covers — recon (subdomain enumeration, asset discovery, fingerprinting, HackerOne scope, source code audit), pre-hunt learning (disclosed reports, tech stack research, mind maps, threat modeling), vulnerability hunting (IDOR, SSRF, XSS, auth bypass, CSRF, race conditions, SQLi, XXE, file upload, business logic, GraphQL, HTTP smuggling, cache poisoning, OAuth, timing side-channels, OIDC, SSTI, subdomain takeover, cloud misconfig, ATO chains, agentic AI), LLM/AI security testing (chatbot IDOR, prompt injection, indirect injection, ASCII smuggling, exfil channels, RCE via code tools, system prompt extraction, ASI01-ASI10), A-to-B bug chaining (IDOR→auth bypass, SSRF→cloud metadata, XSS→ATO, open redirect→OAuth theft, S3→bundle→secret→OAuth), bypass tables (SSRF IP bypass, open redirect bypass, file upload bypass), language-specific grep (JS prototype pollution, Python pickle, PHP type juggling, Go template.HTML, Ruby YAML.load, Rust unwrap), and reporting (7-Question Gate, 4 validation gates, human-tone writing, templates by vuln class, CVSS 3.1, PoC generation, always-rejected list, conditional chain table, submission checklist). Use when you need the local install path of a tool / wordlist / clone for a hunt, or as the full-workflow variant when operating from this local toolkit; for general routing use the bug-bounty skill. 中文触发词：漏洞赏金、安全测试、渗透测试、漏洞挖掘、信息收集、子域名枚举、XSS测试、SQL注入、SSRF、安全审计、漏洞报告
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.
Complete bug bounty workflow — recon (subdomain enumeration, asset discovery, fingerprinting, HackerOne scope, source code audit), pre-hunt learning (disclosed reports, tech stack research, mind maps, threat modeling), vulnerability hunting (IDOR, SSRF, XSS, auth bypass, CSRF, race conditions, SQLi, XXE, file upload, business logic, GraphQL, HTTP smuggling, cache poisoning, OAuth, timing side-channels, OIDC, SSTI, subdomain takeover, cloud misconfig, ATO chains, agentic AI), LLM/AI security testing (chatbot IDOR, prompt injection, indirect injection, ASCII smuggling, exfil channels, RCE via code tools, system prompt extraction, ASI01-ASI10), A-to-B bug chaining (IDOR→auth bypass, SSRF→cloud metadata, XSS→ATO, open redirect→OAuth theft, S3→bundle→secret→OAuth), bypass tables (SSRF IP bypass, open redirect bypass, file upload bypass), language-specific grep (JS prototype pollution, Python pickle, PHP type juggling, Go template.HTML, Ruby YAML.load, Rust unwrap), and reporting (7-Question Gate, 4 validation gates, human-tone writing, templates by vuln class, CVSS 3.1, PoC generation, always-rejected list, conditional chain table, submission checklist). Use for ANY bug bounty task — starting a new target, doing recon, hunting specific vulns, auditing source code, testing AI features, validating findings, or writing reports. 中文触发词：漏洞赏金、安全测试、渗透测试、漏洞挖掘、信息收集、子域名枚举、XSS测试、SQL注入、SSRF、安全审计、漏洞报告
Bugcrowd-specific reporting tactics complementing report-writing: VRT category search-and-fallback strategy when no exact match exists, manual severity override when VRT defaults underrate impact, severity-request paragraph as first body section, OOS-clause rebuttal templates (rate limiting on auth-flow endpoints, debug-info framing, user-enumeration with sensitive PII, theoretical-issue counter), chained-finding cross-reference patterns, target selection for QA-vs-prod programs, researcher-side hygiene (Bugcrowdninja email alias, account state restoration, friendly-tester posture). Use when filing a Bugcrowd submission, when VRT default seems wrong, when triager closes as OOS or downgrades severity, when chaining linked submissions, or when scope distinguishes production from QA. Pairs with report-writing and triage-validation.
Build an exploit chain — given bug A, finds B and C to combine for higher severity and payout. Knows common chain patterns: IDOR→ATO, SSRF→cloud metadata, XSS→ATO, open redirect→OAuth theft, S3→bundle→secret→OAuth. Usage: /chain
Cloud IAM red-team attack chain across AWS, Azure, GCP — focused on EXTERNAL exploitation paths and post-credential-discovery privilege analysis. Covers IAM enumeration (aws iam, az role, gcloud iam), STS/AssumeRole chaining, Azure Managed Identity abuse (via SSRF/leak), GCP service account JSON abuse, IMDSv1/v2 attacks via SSRF, K8s ServiceAccount token privilege analysis once held (token discovery / cluster exposure is owned by hunt-k8s), role-trust-policy confused-deputy, cross-account assume-role enumeration, IAM privilege escalation patterns (24+ AWS, 8+ Azure, 6+ GCP), and AWS Cognito Identity Pool unauthenticated-role attack chain (GetId → GetCredentialsForIdentity → IAM role abuse). Built for the case where recon yields a credential (key, JSON, token) and you need to know what it grants and how to escalate. Use when an AWS key / Azure secret / GCP service account JSON / K8s SA token surfaces from a code repo, JS bundle, APK, breach corpus, or SSRF chain.