Claude AI Cyber Security Skills

Hunt reflected, stored, and DOM-based Cross-Site Scripting (XSS) including CSP bypass, polyglot payloads, mutation XSS (mXSS), markdown XSS, and template XSS. Use when the user has identified a parameter or input that reflects to the page, or wants to test for XSS in a specific input.

Hunt Server-Side Template Injection (SSTI) in Jinja2, Twig, Freemarker, Velocity, Smarty, ERB, Handlebars, Mustache, and Spring (SpEL). Use when input is reflected in a way that suggests template rendering — error pages, email templates, PDF generators, dynamic content systems.

Hunt file upload vulnerabilities — bypass content-type/extension/magic-byte/size filters, achieve XSS via SVG/HTML upload, achieve RCE via .phtml/.jsp/.htaccess, exploit path traversal in filenames, and use polyglot files. Use when an endpoint accepts file uploads.

Hunt JSON Web Token (JWT) vulnerabilities — alg=none bypass, RS256→HS256 key confusion, weak HMAC secret cracking, kid path traversal, JWKS injection, jku/x5u header attacks, embedded JWK confusion, expired-token acceptance, claim mutability, and token replay. Use when an app uses JWT for authentication or stateless sessions.