[Hardening] F-12: Absence of Per-Account or Per-User Source CIDR Allowlist.

### The required feature described as a wish

**Description:** CloudStack does not provide a built-in mechanism to restrict per-account or per-user access to a defined set of source IP addresses or CIDR ranges. Any IP address that can reach the management plane can attempt to authenticate as any account.

**Affected Components:** Management UI / API

**Impact:** Without source IP allowlisting, a stolen API key or compromised credential set can be used from any network location globally. There is no network-level control to limit the blast radius of a credential compromise. High-privilege service accounts are particularly at risk, as they can be accessed from unexpected locations without raising any flags.

**Steps to Reproduce:**
- This finding is not directly reproducible since it reflects the absence of a control.

**Recommended Remediation:** Implement a per-account or per-user source CIDR allowlist field in the data model. Requests originating from IPs outside the defined allowlist should be rejected and logged as a security event.

El issue identifica la Management UI/API, el modelo de datos de la cuenta o del usuario, las comprobaciones de la IP de origen de las solicitudes y el registro de Security-Events, pero no indica archivos ni tests. Empieza por localizar esos puntos de entrada y seguir el flujo de autenticación y autorización de las solicitudes a la API. La finalización debe incluir una política CIDR definida por cuenta o por usuario, el rechazo fuera de la política y Security-Events registrados, con cobertura del comportamiento relevante.

Escrito por el modelo de indexación a partir del texto del issue.