security-review

Guidance for infrastructure, container and deployment security.

When this skill activates

• Security review of infrastructure configuration
• Secrets and credentials management
• Container or service hardening
• Questions about exposed ports or permissions
• Vulnerability scanning and CVEs
• TLS/SSL configuration

Quick checklist

Secrets & Credentials

• No hardcoded secrets in code or configuration
• Secrets injected via secret store or environment variables
• .env files excluded from versioning (.gitignore)
• Secret rotation documented
• No credentials in logs

Containers

• Non-root user
• Capabilities dropped (no --privileged)
• Images scanned for vulnerabilities
• Exposed ports minimized
• Read-only filesystem when possible

Network

• Ports exposed only when necessary
• TLS enabled for external communications
• Internal network isolated for internal services
• No debug port exposed in production

Permissions

• Least privilege principle applied
• File permissions verified (no 777)
• Volume access restricted
• Service accounts with minimal permissions

CI/CD

• Secrets via CI secret store (not plaintext in pipeline)
• Signed images if shared registry
• No root push to registry
• Vulnerability scanning in pipeline

SSRF (server fetching a user-supplied URL)

For link previews, scrapers, PDF capture, webhooks — any server-side fetch of a user URL:

• Validate every request actually emitted, not just the input URL. A public URL that 30x-redirects to 127.0.0.1 / a private IP is the classic bypass; JS navigations (headless browser) are vectors too.
• Disable transparent redirect following (follow_redirects=False) and re-run the host/IP check on each hop before connecting; cap the redirect count.
• For headless browsers (Playwright/Puppeteer), intercept navigation requests and abort those resolving to internal hosts.
• Block private/loopback/reserved/link-local IPs and non-http(s) schemes after DNS resolution.
• Residual risk — DNS rebinding: validation resolves the name, the HTTP client re-resolves at connect time. Closing it requires pinning the connection to the validated IP (custom transport). Document the limitation if you don't close it.

Key principles

1. Least privilege — Each component only accesses what it needs
2. Defense in depth — No single security layer
3. Secrets = ephemeral — Regular rotation, never hardcoded
4. Audit trail — Every sensitive action must be traceable

Anti-patterns

• --privileged or --cap-add=ALL without justification
• Plaintext secrets in docker-compose.yml or CI environment variables
• Port 22 exposed on a container
• Base image never updated (accumulated CVEs)
• Wildcard permissions (chmod 777, 0.0.0.0 without restriction)
• Disabling TLS "because it's internal network"

When to escalate to @infra-expert

Use the full agent for:

• Full security audit of a stack
• Vulnerability analysis and remediation plan
• Secure network architecture (isolation, segmentation)
• CI/CD chain review for supply chain risks
• When structured review format with criticality levels is needed