security.md

Security

• Never interpolate user input into SQL. Use parameterised queries or where(key: value).
• Always use strong parameters. Never params.permit!.
• Scope all queries to the current user or use Pundit authorisation.
• Every controller must have authentication unless explicitly public.
• Never use raw, html_safe, or <%== with user-supplied data.
• Never skip CSRF verification for browser-facing controllers.
• Filter sensitive params in logs: passwords, tokens, secrets, API keys.
• Never render json: model without explicit only: — whitelist attributes.
• Never redirect to params[:return_to] without validation.
• Use array form for system commands: system("cmd", arg), never system("cmd #{arg}").
• Run bundle audit regularly. Keep gems updated for security patches.