Skip to content
validating-cors-policies logo

Cors Policy Validator

validating-cors-policies

Validate CORS policies for security issues and misconfigurations. Use when reviewing cross-origin resource sharing. Trigger with 'validate CORS', 'check CORS policy', or 'review cross-origin'.

SKILL.md

Full skill instructions

Cors Policy Validator

This skill provides automated assistance for cors policy validator tasks.

Overview

This skill empowers Claude to assess the security and correctness of CORS policies. By leveraging the cors-policy-validator plugin, it identifies misconfigurations and potential vulnerabilities in CORS settings, helping developers build more secure web applications.

How It Works

  1. Analyze CORS Configuration: The skill receives the CORS configuration details, such as headers or policy files.
  2. Validate Policy: It utilizes the cors-policy-validator plugin to analyze the provided configuration against established security best practices.
  3. Report Findings: The skill presents a detailed report outlining any identified vulnerabilities or misconfigurations in the CORS policy.

When to Use This Skill

This skill activates when you need to:

  • Validate a CORS policy for a web application.
  • Check the CORS configuration of an API endpoint.
  • Identify potential security vulnerabilities in existing CORS implementations.

Examples

Example 1: Validating a CORS Policy File

User request: "Validate the CORS policy in cors_policy.json"

The skill will:

  1. Read the cors_policy.json file.
  2. Use the cors-policy-validator plugin to analyze the CORS configuration.
  3. Output a report detailing any identified vulnerabilities or misconfigurations.

Example 2: Checking CORS Headers for an API Endpoint

User request: "Check CORS headers for the API endpoint at https://example.com/​api"

The skill will:

  1. Fetch the CORS headers from the specified API endpoint.
  2. Use the cors-policy-validator plugin to analyze the headers.
  3. Output a report summarizing the CORS configuration and any potential issues.

Best Practices

  • Configuration Source: Always specify the source of the CORS configuration (e.g., file path, URL) for accurate validation.
  • Regular Validation: Regularly validate CORS policies, especially after making changes to the application or API.
  • Heuristic Analysis: Consider supplementing validation with manual review and heuristic analysis to catch subtle vulnerabilities.

Integration

This skill can be integrated with other security-related plugins to provide a more comprehensive security assessment. For example, it can be used in conjunction with vulnerability scanning tools to identify potential cross-site scripting (XSS) vulnerabilities related to CORS misconfigurations.

Prerequisites

  • Access to codebase and configuration files in {baseDir}/
  • Security scanning tools installed as needed
  • Understanding of security standards and best practices
  • Permissions for security analysis operations

Instructions

  1. Identify security scan scope and targets
  2. Configure scanning parameters and thresholds
  3. Execute security analysis systematically
  4. Analyze findings for vulnerabilities and compliance gaps
  5. Prioritize issues by severity and impact
  6. Generate detailed security report with remediation steps

Output

  • Security scan results with vulnerability details
  • Compliance status reports by standard
  • Prioritized list of security issues by severity
  • Remediation recommendations with code examples
  • Executive summary for stakeholders

Error Handling

If security scanning fails:

  • Verify tool installation and configuration
  • Check file and directory permissions
  • Validate scan target paths
  • Review tool-specific error messages
  • Ensure network access for dependency checks

Resources

  • Security standard documentation (OWASP, CWE, CVE)
  • Compliance framework guidelines (GDPR, HIPAA, PCI-DSS)
  • Security scanning tool documentation
  • Vulnerability remediation best practices

More Security skills

supabase logo
Security

supabase

Handles the full Supabase workflow from schema changes to deployment, with built-in security guardrails that catch common traps like RLS...

2.7K 308.9K
View

Comprehensive guides and best practices for Neon Serverless Postgres, covering setup, connection methods, authentication, and platform APIs.

98 216.2K
View

Guide for setting up and using Firebase Authentication. Use this skill when the user's app requires user sign-in, user management, or secure data access using auth rules.

462 163.8K
View

A skill to evaluate how secure Firestore security rules are. Use this when Firestore security rules are updated to ensure that the generated rules are extremely secure and robust.

462 127.7K
View

Official skill for integrating Firebase AI Logic (Gemini API) into web applications. Covers setup, multimodal inference, structured output, and security.

462 125.1K
View

Complete Better Auth server and client setup with database adapters, session management, plugins, and security configuration.

222 118.2K
View

Deploy and manage projects on Vercel using token-based authentication. Use when working with Vercel CLI using access tokens rather than interactive login — e.g. "deploy to vercel", "set up vercel", "add environment variables to vercel".

31.9K 116.1K
View
cloudflare logo
Security

cloudflare

Complete Cloudflare platform integration with decision trees for compute, storage, AI, networking, security, and infrastructure-as-code.

3K 110.7K
View

Run Azure compliance and security audits with azqr plus Key Vault expiration checks. Covers best-practice assessment, resource review, policy/compliance validation, and security posture checks. WHEN: compliance scan, security audit, BEFORE running azqr (compliance cli tool), Azure best practices, Key Vault expiration check, expired certificates, expiring secrets, orphaned resources, compliance assessment.

253 103K
View
gws-gmail logo
Security

gws-gmail

Send, read, and manage Gmail messages, drafts, labels, and account settings.

31.2K 78.9K
View

Comprehensive website auditing across 230+ rules in 21 categories including SEO, performance, security, and accessibility.

94 72.3K
View
gws-shared logo
Security

gws-shared

Shared authentication, CLI syntax, and output formatting patterns for gws Google Workspace commands.

31.2K 63.4K
View

Security AI tools

StarByFace logo
Security

StarByFace

Discover your celebrity doppelgänger with StarByFace!

Free
View
GeoSpy logo
Security

GeoSpy

GeoSpy: Pricing, Features, FAQs, and Alternatives for AI Teams

Free
View

Detect AI-generated voices to protect against audio fraud.

Paid
View

Ensure Your Content's Originality with AI Plagiarism Checker

Freemium
View
Img Upscaler logo
Security

Img Upscaler

Upscale images by 400% without quality loss

Freemium
View
AICheatCheck logo
Security

AICheatCheck

Accurately Detect AI-Generated Content with TheChecker.AI

Free
View
D
Security

Detect GPT

Chrome extension that detects and flags AI-generated content

Free
View