pentest-client-advanced

Assess client-side security weaknesses across CORS, WebSocket, clickjacking, postMessage, CSS injection, and storage.

299|56|Updated Jan 13, 2026

Search Tags:#clickjacking #client-side #web-security #cors #websocket #storage #pentest

Ready to run

npx skills add https://github.com/jd-opensource/JoySafeter --skill pentest-client-advanced

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: pentest-client-advanced
Source: https://github.com/jd-opensource/JoySafeter/tree/main/skills/pentest-client-advanced
Command: npx skills add https://github.com/jd-opensource/JoySafeter --skill pentest-client-advanced

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

Advanced client-side security testing is needed to uncover vulnerabilities that occur in the browser and client-side interactions, including cross-origin actions, messaging, and storage, which are often overlooked by server-focused assessments.

Core Features & Use Cases

CORS misconfiguration assessment across origins and credentials handling.
WebSocket security testing for CSWSH, origin validation, and message injection.
Clickjacking analysis with frame-ancestors and X-Frame-Options checks.
PostMessage abuse detection with origin validation and safe handling of messages.
CSS injection and browser storage testing for in-page style manipulation and localStorage/IndexedDB exposure.
PoC generation to demonstrate and document vulnerabilities with reproducible proofs.

Quick Start

Run a client-side security test against a target page to generate PoCs for the identified vulnerabilities.

Frequently Asked Questions about pentest-client-advanced

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I test for CORS misconfigurations in modern web applications?▼

To test for CORS misconfigurations, assess cross-origin requests and credential handling across origins. This skill identifies unsafe cross-origin configurations and generates PoCs to document unsafe access control behavior.

How do I detect postMessage and WebSocket security vulnerabilities?▼

Detect postMessage and WebSocket vulnerabilities by evaluating origin validation and message injection vectors. This skill assesses unsafe message handling and generates proof-of-concept payloads to confirm cross-site WebSocket hijacking risks.

How can I test for clickjacking and CSS injection vulnerabilities?▼

Test clickjacking and CSS injection by analyzing frame-ancestors and X-Frame-Options headers for dynamic content. This skill identifies missing protections and generates PoCs to demonstrate in-page style manipulation and framing risks.

Does client-side security testing cover browser storage like localStorage and IndexedDB?▼

Yes, client-side security testing covers browser storage by evaluating localStorage and IndexedDB exposure. This skill assesses in-browser storage mechanisms to identify data leakage and insecure storage implementations.

Can I generate reproducible PoCs during advanced client-side pentesting?▼

Yes, you can generate reproducible PoCs during advanced client-side pentesting. This skill provides structured test vectors and generates proofs of concept to demonstrate and document vulnerabilities across cross-origin apps.

What are the limitations of client-side security testing for enterprise environments?▼

Client-side security testing focuses on browser interactions and may miss server-side flaws. This skill requires documented prerequisites without external tooling and applies deterministic workflows to ensure safety checks across cross-origin apps.