Security Risk

Identify security and privacy risks and propose mitigations.

Workflow

1. Review data flows and trust boundaries.
2. Scan for injection, logging, auth, and cross-origin risks.
3. Validate privacy boundaries (what is and is not synced/stored/transmitted).
4. Summarize risks and mitigations.

Cross-Origin Security Checks

For backend APIs called from browsers:

• Treat CORS as an explicit allowlist decision per origin.
• Verify Access-Control-Allow-Origin is echoed from a vetted allowlist (no wildcard for credentialed/sensitive flows).
• Ensure disallowed origins receive no allow-origin header.
• Add Vary: Origin when origin-based responses differ.
• Confirm preflight and non-preflight responses enforce consistent origin policy.
• Confirm config docs and runtime env origins are aligned to avoid accidental exposure or outages.

Sync Privacy Checks

For encrypted sync payload systems:

• Verify server treats encrypted payload as opaque unless schema parsing is explicitly required.
• Confirm migrations do not broaden synced data classes (e.g., no amounts/PII unless approved).
• Confirm migration retention policy is documented (intro date + removal-eligible date), that the 2-month window is for in-repo migration support, and that legacy storage cleanup only runs after successful migrated write during the active window.
• Confirm logs/telemetry do not include sensitive payload content.

Output Format

• Risks identified
• Mitigations
• Residual risk

References

• Threat modeling worksheet