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DOM XSS via postMessage

Community

Securely handle cross-origin messages.

Software Engineering#security#vulnerability#xss#web security#dom#postmessage
Authorallsmog
Version1.0.0
Installs0

System Documentation

What problem does it solve?

This Skill addresses the critical security vulnerability of DOM-based Cross-Site Scripting (XSS) that arises from insecure handling of postMessage API calls, protecting applications from malicious data injection.

Core Features & Use Cases

  • Vulnerability Detection: Identifies insecure postMessage listeners that lack origin validation and trace data flow to dangerous DOM sinks.
  • Exploitation Analysis: Explains how vulnerabilities can be chained with other attack vectors like SSRF to bypass security restrictions.
  • Remediation Guidance: Provides clear, actionable steps and code examples for fixing postMessage vulnerabilities and implementing protective measures.
  • Use Case: A developer can use this skill to audit their web application for postMessage related XSS flaws, understand the risks, and implement the recommended fixes to secure their site.

Quick Start

Audit the current project for DOM XSS vulnerabilities related to postMessage.

Dependency Matrix

Required Modules

None required

Components

references

💻 Claude Code Installation

Recommended: Let Claude install automatically. Simply copy and paste the text below to Claude Code.

Please help me install this Skill:
Name: DOM XSS via postMessage
Download link: https://github.com/allsmog/vuln-scout/archive/main.zip#dom-xss-via-postmessage

Please download this .zip file, extract it, and install it in the .claude/skills/ directory.
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