rule_id: codeguard-0-logging

Logging & Monitoring

Produce structured, privacy‑aware telemetry that supports detection, response, and forensics without exposing secrets.

What to Log

• Authn/authz events; admin actions; config changes; sensitive data access; input validation failures; security errors.
• Include correlation/request IDs, user/session IDs (non‑PII), source IP, user agent, timestamps (UTC, RFC3339).

How to Log

• Structured logs (JSON) with stable field names; avoid free‑form text for critical signals.
• Sanitize all log inputs to prevent log injection (strip CR/LF/delimiters); validate data from other trust zones.
• Redact/tokenize secrets and sensitive fields; never log credentials, tokens, recovery codes, or raw session IDs.
• Ensure integrity: append‑only or WORM storage; tamper detection; centralized aggregation; access controls and retention policies.

Detection & Alerting

• Build alerts for auth anomalies (credential stuffing patterns, impossible travel), privilege changes, excessive failures, SSRF indicators, and data exfil patterns.
• Tune thresholds; provide runbooks; ensure on‑call coverage; test alert flows.

Storage & Protection

• Isolate log storage (separate partition/database); strict file/directory permissions; store outside web‑accessible locations.
• Synchronize time across systems; use secure protocols for transmission; implement tamper detection and monitoring.

Privacy & Compliance

• Maintain data inventory and classification; minimize personal data in logs; honor retention and deletion policies.
• Provide mechanisms to trace and delete user‑linked log data where required by policy.

Implementation Checklist

• JSON logging enabled; log injection sanitization active; redaction filters active; correlation IDs on all requests.
• Isolated log storage with tamper detection; centralized log pipeline with integrity protections; retention configured.
• Security alerts defined and tested; dashboards and reports in place.

Validation

• Unit/integration tests assert presence/absence of key fields; redaction unit tests.
• Periodic audits for secret/PII leakage; tabletop exercises for incident workflows.