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security-headers-configuration

Imported from https://github.com/secondsky/claude-skills.

Packaged view

This page reorganizes the original catalog entry around fit, installability, and workflow context first. The original raw source lives below.

Stars
84
Hot score
93
Updated
March 20, 2026
Overall rating
C4.5
Composite score
4.5
Best-practice grade
A92.0

Install command

npx @skill-hub/cli install secondsky-claude-skills-security-headers-configuration

Repository

secondsky/claude-skills

Skill path: plugins/security-headers-configuration/skills/security-headers-configuration

Imported from https://github.com/secondsky/claude-skills.

Open repository

Best for

Primary workflow: Run DevOps.

Technical facets: Full Stack, Security.

Target audience: everyone.

License: Unknown.

Original source

Catalog source: SkillHub Club.

Repository owner: secondsky.

This is still a mirrored public skill entry. Review the repository before installing into production workflows.

What it helps with

  • Install security-headers-configuration into Claude Code, Codex CLI, Gemini CLI, or OpenCode workflows
  • Review https://github.com/secondsky/claude-skills before adding security-headers-configuration to shared team environments
  • Use security-headers-configuration for development workflows

Works across

Claude CodeCodex CLIGemini CLIOpenCode

Favorites: 0.

Sub-skills: 0.

Aggregator: No.

Original source / Raw SKILL.md

---
name: security-headers-configuration
description: Configures HTTP security headers to protect against XSS, clickjacking, and MIME sniffing attacks. Use when hardening web applications, passing security audits, or implementing Content Security Policy.
---

# Security Headers Configuration

Implement HTTP security headers to defend against common browser-based attacks.

## Essential Headers

| Header | Purpose | Value |
|--------|---------|-------|
| HSTS | Force HTTPS | `max-age=31536000; includeSubDomains` |
| CSP | Restrict resources | `default-src 'self'` |
| X-Frame-Options | Prevent clickjacking | `DENY` |
| X-Content-Type-Options | Prevent MIME sniffing | `nosniff` |

## Express Implementation

```javascript
const helmet = require('helmet');

app.use(helmet());

// Custom CSP
app.use(helmet.contentSecurityPolicy({
  directives: {
    defaultSrc: ["'self'"],
    scriptSrc: ["'self'", "'unsafe-inline'"],
    styleSrc: ["'self'", "'unsafe-inline'"],
    imgSrc: ["'self'", "data:", "https:"],
    connectSrc: ["'self'", "https://api.example.com"],
    fontSrc: ["'self'", "https://fonts.gstatic.com"],
    frameAncestors: ["'none'"]
  }
}));
```

## Nginx Configuration

```nginx
add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;
add_header X-Frame-Options "DENY" always;
add_header X-Content-Type-Options "nosniff" always;
add_header X-XSS-Protection "1; mode=block" always;
add_header Referrer-Policy "strict-origin-when-cross-origin" always;
add_header Permissions-Policy "geolocation=(), microphone=(), camera=()" always;
add_header Content-Security-Policy "default-src 'self'; script-src 'self'" always;
```

## Verification Tools

- [Security Headers](https://securityheaders.com/)
- [Mozilla Observatory](https://observatory.mozilla.org/)
- [CSP Evaluator](https://csp-evaluator.withgoogle.com/)

## Security Headers Checklist

- [ ] HSTS enabled with long max-age
- [ ] CSP configured and tested
- [ ] X-Frame-Options set to DENY
- [ ] X-Content-Type-Options set to nosniff
- [ ] Referrer-Policy configured
- [ ] Permissions-Policy disables unused features

## Additional Implementations

See [references/python-apache.md](references/python-apache.md) for:
- Python Flask security headers middleware
- Flask-Talisman library configuration
- Apache .htaccess configuration
- Header testing script

## Common Mistakes

- Setting CSP to report-only permanently
- Using overly permissive policies
- Forgetting to test after changes
- Not including all subdomains in HSTS
security-headers-configuration | SkillHub