web2-vuln-classes
Complete reference for 26 web2 bug classes with root causes, detection patterns, bypass tables, exploit techniques, and real paid examples. Covers IDOR, auth bypass, XSS, SSRF (11 IP bypass techniques), SQLi, business logic, race conditions, OAuth/OIDC, file upload (10 bypass techniques), GraphQL, LLM/AI (ASI01-ASI10 agentic framework), API misconfig (mass assignment, JWT attacks, prototype pollution, CORS), ATO taxonomy (9 paths), SSTI (Jinja2/Twig/Freemarker/ERB/Spring), subdomain takeover, cloud/infra misconfigs, HTTP smuggling (CL.TE/TE.CL/H2.CL), cache poisoning, MFA bypass (7 patterns), SAML attacks (XSW/comment injection/signature stripping), error disclosure / debug endpoints (stack trace regex per framework, chain templates), CSS injection (attribute-selector exfiltration, opacity clickjacking, @import). LFI / file inclusion -> RCE (php://filter source disclosure, iconv filter-chain RCE with no upload, log/environ poisoning, .user.ini/.htaccess auto_prepend, data:// + expect:// wrappers, session inclusion, traversal bypass table). Insecure deserialization (PHP __wakeup bypass / phar:// POP chains, Java ysoserial CommonsCollections gadgets + magic bytes, Python pickle __reduce__ + signed-cookie forgery, Node node-serialize). Dependency confusion / supply chain (internal package-name discovery, unclaimed-name confirmation, callback-only PoC, npm/pip/Maven/RubyGems variants). Use when hunting a specific vuln class or studying what makes bugs pay.
Security
3 findings: 2 critical severity, 1 high severity. Installing this skill is not recommended: please review these findings carefully if you do intend to do so.
E005: Suspicious download URL detected in skill instructions.
What this means
Detected a suspicious URL in the skill instructions that could lead the agent to download and execute malicious scripts or binaries. This includes links to executables from untrusted sources, typosquatting of official packages, URL shorteners that obscure the destination, and personal file hosting services.
Why it was flagged
Yes — many of these URLs are attacker-controlled, obfuscated/typosquatted (@, %00, homoglyphs), or point at cloud metadata / OOB callback endpoints and S3/Firebase hosts, which are high‑risk vectors for SSRF, credential exfiltration, redirect/typosquat attacks and hosting/distributing malicious payloads.
E006: Malicious code pattern detected in skill scripts.
What this means
Detected high-risk code patterns in the skill content — including its prompts, tool definitions, and resources — such as data exfiltration, backdoors, remote code execution, credential theft, system compromise, supply chain attacks, and obfuscation techniques.
Why it was flagged
The document contains explicit, actionable offensive techniques that demonstrate deliberate data-exfiltration and remote-execution behaviors (e.g., XSS/CSS exfil payloads, postMessage->fetch to attacker endpoints, SSRF to metadata, LFI/php://filter RCE chains, deserialization gadget OOB callbacks, and a dependency-confusion beacon that performs DNS/HTTP callbacks), which are clearly dual-use but include intentionally malicious flows such as hidden callbacks and credential/secret theft patterns.
W007: Insecure credential handling detected in skill instructions.
What this means
The skill handles credentials insecurely by requiring the agent to include secret values verbatim in its generated output. This exposes credentials in the agent’s context and conversation history, creating a risk of data exfiltration.
Why it was flagged
The skill contains explicit examples that tell an agent to read sensitive files or values (e.g., ~/.aws/credentials, user.ssn, API keys) and embed them verbatim into exfil channels (email/image/HTTP tool calls), which would force an LLM/agent to handle and output secrets directly.
- Repository
- shuvonsec/claude-bug-bounty
- Commit
0826b13
- Audited
- Security analysis
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