Skip to content
Agentmart
Submit a tool

performing-security-headers-audit

Auditing HTTP security headers including CSP, HSTS, X-Frame-Options, and cookie attributes to identify missing or misconfigured browser-level protections.

Skill by Njones17

IndexedMIT★ 24
Write a review

Install

Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install skill/njones17-performing-security-headers-audit

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

Get the weekly diff

The weekly diff: one email a week with new agent tools, notable updates and grade changes, plus security alerts for tools you follow. Double opt-in, one-click unsubscribe.

We use your email only for this newsletter. Privacy

About

Auditing HTTP security headers including CSP, HSTS, X-Frame-Options, and cookie attributes to identify missing or misconfigured browser-level protections.

Use cases: security

No reviews yet. Installed it? Reviews come from verified installers only. How reviews work

Permissions

What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

Tools
No tools found
Secrets
None asked for
Install scripts
None found

Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/performing-security-headers-audit

What's inside

Skill name
performing-security-headers-audit
Description
Auditing HTTP security headers including CSP, HSTS, X-Frame-Options, and cookie attributes to identify missing or misconfigured browser-level protections.
License
MIT
Instructions
298 lines in SKILL.md · view on GitHub

Before installing

  • Instructions call the network

Files (1)

  • SKILL.md

SKILL.md (first lines)

# Performing Security Headers Audit

## When to Use

- During authorized web application security assessments as a standard configuration review
- When evaluating browser-level protections against XSS, clickjacking, and data leakage
- For compliance assessments requiring security header implementation (PCI DSS, SOC 2)
- When performing initial reconnaissance to identify easy-win security improvements
- During CI/CD pipeline security gate checks for new deployments

## Prerequisites

- **Authorization**: Written scope for the target application (header review is low-risk)
- **curl**: For fetching response headers from target endpoints
- **SecurityHeaders.com**: Online scanner for quick header assessment
- **Mozilla Observatory**: Mozilla's web security testing tool
- **Burp Suite**: For comprehensive header analysis across multiple pages
- **Browser DevTools**: For examining headers and CSP violations in real-time

## Workflow

### Step 1: Collect Security Headers from Target

Retrieve and catalog all security-related response headers.

```bash
# Fetch all response headers
curl -s -I "https://target.example.com/" | grep -iE \
  "(strict-transport|content-security|x-frame|x-content-type|x-xss|referrer-policy|permissions-policy|feature-policy|x-permitted|cross-origin|set-cookie|server|x-powered-by|cache-control)"

# Check headers across multiple pages
PAGES=("/" "/login" "/api/health" "/admin" "/account/settings" "/static/app.js")

for page in "${PAGES[@]}"; do
  echo "=== $page ==="
  curl -s -I "https://target.example.com$page" 2>/dev/null | grep -iE \
    "(strict-transport|content-security|x-frame|x-content-type|x-xss|referrer-policy|permissions-policy|set-cookie|server|x-powered)"
  echo
done

# Check both HTTP and HTTPS responses
echo "=== HTTP Response ==="
curl -s -I "http://target.example.com/" | head -20
echo "=== HTTPS Response ==="
curl -s -I "https://target.example.com/" | head -20
```

### Step 2: Assess Transport Security (HSTS)

Evaluate HTTP Strict Transport Security configuration.

```bash
# Check HSTS header
curl -s -I "https://target.example.com/" | grep -i "strict-transport-security"

# Expected: Strict-Transport-Security: max-age=31536000; includeSubDomains; preload

# Verify HSTS attributes:
# max-age: Should be >= 31536000 (1 year) for preload eligibility
# includeSubDomains: Protects all subdomains
# preload: Eligible for browser HSTS preload list

# Check if HTTP redirects to HTTPS
curl -s -I "http://target.example.com/" | head -5
# Should be 301/302 redirect to https://

# Check if HSTS is on the preload list
# Visit: https://hstspreload.org/?domain=target.example.com

# Test for HTTPS-only cookies
curl -s -I "https://target.example.com/login" | grep -i "set-cookie"
# All session cookies should have Secure flag

# Check for mixed content
curl -s "https://target.example.com/" | grep -oP "http://[^\"']+" | head -20
# HTTP resources loaded on HTTPS pages create mixed content vulnerabilities
```

### Step 3: Audit Content Security Policy (CSP)

Analyze CSP headers for effectiveness and potential bypasses.

```bash
# Extract CSP header
CSP=$(curl -s -I "https://target.example.com/" | grep -i "content-security-policy" | cut -d: -f2-)
echo "$CSP"

# Check for dangerous directives:
# 'unsafe-inline' in script-src: Allows inline scripts (XSS risk)
# 'unsafe-eval' in script-src: Allows eval() (XSS risk)
# * in any directive: Allows loading from any origin
# data: in script-src: Allows data: URI scripts
# Missing default-src: No fallback policy

echo "$CSP" | tr ';' '\n' | while read directive; do
  echo "  $directive"
  if echo "$directive" | grep -q "unsafe-inline"; then
    echo "    WARNING: unsafe-inline allows inline script execution"
  fi
  if echo "$directive" | grep -q "unsafe-eval"; then
    echo "    WARNING: unsafe-eval allows eval() calls"
  fi
  if echo "$directive" | grep -q " \* "; then
    echo "    WARNING: wildcard allows loading from any origin"
  fi
done

# Check for CSP report-only (not enforcing)
curl -s -I "https://target.example.com/" | grep -i "content-security-policy-report-only"
# Report-only does NOT block violations, only logs them

# Test CSP with Google's evaluator
# https://csp-evaluator.withgoogle.com/
# Paste the CSP header for automated analysis

# Check for CSP bypass via whitelisted domains
# If CDN domains are whitelisted, check for JSONP endpoints or angular libraries
```

From Njones17/AI-agent-master-cyber-skills-list, MIT.

More from Njones17/AI-agent-master-cyber-skills-list

Signals

Stars
24
Forks
6
Open issues
0
Last commit (this folder)
Mar 6, 2026 (7 months ago)

From GitHub (fetched Oct 24, 2026).

Details

License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

More from Njones17

Cite this page

performing-security-headers-audit skill. Agent Mart. https://agentmart.dev/skills/njones17-performing-security-headers-audit (last updated 2026-10-24)