slack5-1770574304/.sdlc/features/user-preferences/audit.md

Security Audit: User Preferences API

Summary

Overall Assessment: PASS

The User Preferences API feature demonstrates solid security practices. No critical or high-severity findings were identified. The implementation follows secure coding patterns throughout: parameterized SQL queries, strict input binding with unknown field rejection, proper authentication gating, and correct authorization checks with ownership verification. A small number of medium and low-severity findings relate to the auth toggle pattern and lack of rate limiting, both of which are platform-level concerns rather than feature-specific vulnerabilities.

Static Analysis Results

Tool	Result
go vet ./...	PASS — No issues found
golangci-lint	Not available in environment; skipped

OWASP Assessment

Category	Status	Notes
A01 - Broken Access Control	PASS	Self-access enforced for writes (user.ID != userID → 403). Admin read-only via HasRole("admin"). Tests cover self-access, admin read, admin write denial, and cross-user denial.
A02 - Cryptographic Failures	PASS	No custom cryptography. JWT validation delegated to pkg/auth framework. No sensitive data stored beyond user ID.
A03 - Injection	PASS	All SQL uses parameterized queries ($1, $2 placeholders). No string interpolation in SQL. No command execution. No template rendering.
A04 - Insecure Design	PASS	Hexagonal architecture cleanly separates concerns. Domain validation is pure and testable. Authorization logic is explicit in handlers.
A05 - Security Misconfiguration	INFO	AUTH_ENABLED=false default in .env.example — auth is opt-in via environment toggle. Acceptable for local dev, but must be true in production. See Medium Finding M1.
A06 - Vulnerable Components	PASS	Standard library + well-known dependencies (go-chi, lib/pq). No known vulnerable components.
A07 - Auth Failures	PASS	Auth middleware applied to both endpoints via route group. Unauthenticated requests rejected with 401 when auth is enabled.
A08 - Data Integrity	PASS	Strict JSON binding (BindAndValidateStrict) rejects unknown fields. Struct tag validation constrains enum values. Domain-layer validation provides defense in depth.
A09 - Logging & Monitoring	PASS	Preference updates logged with user_id. DB errors logged server-side, generic message returned to client. No PII logged beyond user ID.
A10 - SSRF	PASS	No outbound HTTP requests. No user-controlled URLs.

Critical Findings

None.

High Findings

None.

Medium Findings

M1: Auth Toggle Defaults to Disabled

Location: internal/config/config.go:31, .env.example:17

Description: Authentication is controlled by the AUTH_ENABLED environment variable, which defaults to false. When auth is disabled, the preference endpoints are accessible without any authentication, meaning any client can read/write any user's preferences. While the handler still checks auth.GetUser(ctx) and returns 401 if nil, the auth middleware that populates the user context is not applied when AUTH_ENABLED=false.

Risk: If deployed to production without explicitly setting AUTH_ENABLED=true, all preference endpoints would be unprotected.

Mitigation: This is a platform-level pattern used across all services for local development. Production deployment pipelines should enforce AUTH_ENABLED=true. Consider adding a startup warning when auth is disabled in non-development environments.

M2: No Rate Limiting on Preference Updates

Description: The PUT endpoint has no rate limiting. An authenticated user could make unlimited update requests, potentially causing excessive database writes.

Risk: Low probability given auth requirement, but could enable denial-of-service against the database from a compromised account.

Mitigation: Platform-level rate limiting (e.g., at ingress/API gateway) is the appropriate layer for this. Not a feature-specific concern, but worth noting.

Low Findings

L1: Dev Secret in .env.example

Location: .env.example:18

Description: The .env.example file contains JWT_SECRET=dev-secret-change-in-production. While .env.example is a template and not used in production, the presence of a weak secret value could be accidentally copied to production .env files.

Mitigation: Standard practice for example files. The value is clearly labeled as a dev placeholder. Production secrets should be managed via secret management infrastructure, not .env files.

L2: User ID Logged on Preference Update

Location: internal/service/preferences.go:52

Description: s.logger.Info("preferences updated", "user_id", userID) logs the user ID on every preference update. User IDs are not PII by themselves (they are opaque identifiers), but could be used for correlation.

Mitigation: This is appropriate audit logging. No remediation needed.

Recommendations

1. Ensure production deployment enforces AUTH_ENABLED=true — Validate this in CI/CD pipeline or deployment config (platform concern, not feature-specific).
2. Consider platform-level rate limiting — Apply rate limits at the API gateway layer for all write endpoints.
3. No feature-specific changes required — The implementation follows secure patterns correctly.

Files Audited

File	Lines	Purpose
internal/domain/preferences.go	89	Domain types, validation, defaults
internal/domain/errors.go	18	Domain error definitions
internal/port/preferences.go	18	Repository interface
internal/adapter/memory/preferences.go	50	In-memory adapter (tests)
internal/adapter/postgres/preferences.go	95	PostgreSQL adapter with parameterized queries
internal/service/preferences.go	56	Business logic service
internal/service/preferences_test.go	174	Service unit tests
internal/api/handlers/preferences.go	154	HTTP handlers with auth checks
internal/api/handlers/preferences_test.go	321	Handler tests including auth scenarios
internal/api/routes.go	49	Route registration with auth middleware
internal/api/spec.go	79	OpenAPI specification
internal/config/config.go	34	Service configuration
cmd/server/main.go	79	Application wiring
.env.example	21	Environment template