AUTOMATED Payment page script allowlist and integrity controls

Why it Matters

A script inventory says what should load; an allowlist and integrity controls help enforce it. Without enforcement, compromised tag managers, injected templates, or extension changes can add scripts that skim payment pages.

Strong controls around allowed hosts, CSP nonces/hashes, and deployment review make checkout script behavior harder to tamper with silently.

Verification Steps

# Inspect checkout response headers for script-src allowlist
curl -I https://mystore.com/checkout | grep -i content-security-policy

Remediation / Fix Guidance

1. Define allowed script hosts for checkout and payment pages.
2. Use CSP nonces, hashes, or strict allowlists where Magento and extensions allow it.
3. Restrict tag manager permissions and review tag changes.
4. Remove wildcard script sources such as * or broad CDN allowances.
5. Alert when checkout loads a script outside the approved list.

Examples

script-src * 'unsafe-inline' 'unsafe-eval';
# Broad script execution allowed → FAIL

script-src 'self' https://js.payment-provider.example 'nonce-...';
# Limited approved sources → PASS

References

• PCI DSS v4.0.1
• OWASP Top 10 — A05: Security Misconfiguration
• OWASP Top 10 — A08: Software and Data Integrity Failures
• Adobe Commerce — Content Security Policies