Walled garden" used to be the security principle backing SS7 networks. This is no longer the case, and some attackers may benefit from access to these networks to leverage mobile network functions: geolocation, access to subscriber's profile, interception of communications. Mobile network operators now deploy new equipments to detect attacks and protect their customers. These new equipments are expected to be robust against wild traffic and safe. We describe in this talk vulnerabilities we have discovered and what we look into when assessing security of such products.