Agent Skills: Client-Side

Client-Side

Test for client-side vulnerabilities across modern web applications and SPAs.

Techniques

| Type | Key Vectors | |------|-------------| | XSS | Reflected, Stored, DOM-based, framework-specific (React, Vue, Angular) | | CSRF | Token bypass, SameSite cookie bypass, cross-origin requests | | CORS | Misconfigured origins, null origin, wildcard credentials | | Clickjacking | Frame-based, drag-and-drop, multi-step | | DOM-based | DOM sinks, source/sink analysis, JavaScript URL schemes | | Prototype Pollution | Client-side gadgets, server-side pollution, property injection |

Workflow

1. Identify input sources and data flows
2. Classify sink contexts (HTML, attribute, URL, JS, CSS)
3. Enumerate defenses (encoding, CSP, sanitizers, Trusted Types)
4. Craft context-appropriate payloads
5. Validate execution and demonstrate impact
6. Document with reproduction steps and remediation

Reference

• reference/xss*.md - XSS bypass techniques and exploitation
• reference/csrf*.md - CSRF techniques and bypasses
• reference/cors*.md - CORS misconfiguration testing
• reference/clickjacking*.md - Clickjacking techniques
• reference/dom*.md - DOM-based vulnerability testing
• reference/prototype-pollution*.md - Prototype pollution techniques