In a mobile network environment, while core networks are able to manage security threats, mobile stations (MSs) that access the mobile network have little defence capability due to limited hardware resources. Compromised mobile stations can themselves easily become virus agents and threaten the entire network. The Correlative Reacting System (CRS) defined in this Recommendation aims to protect mobile networks against the threats of insecure terminals that do not conform to the security policy of the network, such as terminals that have been compromised.