Two U.S. intelligence agencies published an industry paper on security and resiliency of 5G network slicing. The report, published jointly by the National Security Agency (NSA) and the Cybersecurity and Infrastructure Security Agency (CISA), examines security concerns, design criteria, implementation considerations, and ongoing maintenance.
NSA and CISA are members of the Enduring Security Framework, a public-private working group established to enhance the security of 5G technology for broadband cellular networks. To achieve this, a panel of government and industry experts conducted an extensive review of 5G standalone network slicing and published their findings in two papers: The previous paper identified significant threat vectors to 5G network slices, while the latest report focuses on addressing these threats and providing industry-recognized best practices.
Network slicing refers to an end-to-end logical network that caters to specific capabilities required by different 5G use cases, stressing the importance of security. The new document aims to foster communication among stakeholders and enhance resiliency and security in network slicing. The intended audience should possess familiarity with 5G networks and network slicing, supplementing the information with individual studies on best practices. Advanced monitoring, auditing, and analytical capabilities are necessary to meet evolving service-level requirements.
The document highlights several security concerns related to network slicing, including inter-slice communications, authentication/authorization, security protocols, denial of service, resource exhaustion, side-channel attacks, user equipment connections, shared resources, slice separation, management systems, administrators, and user anonymity. It emphasizes that network slicing is not primarily a security mechanism and should be discussed with infrastructure providers.
However, the document does underscore the benefits, best practices, and risks associated with network slicing, particularly its efficiency in meeting the communication needs of various industries, especially with the adoption of Internet of Things (IoT) devices. Network slicing provides virtual network services that connect user equipment to applications on other devices or servers. It enhances security by isolating network traffic, functions, compute workloads, and storage on a per-slice basis. Customized authentication, authorization, policies, and security measures can be applied, aligning with the Zero Trust Architecture (ZTA) paradigm.
The document discusses principles, concepts, and components of network slicing, including radio access networks, transport networks, and service orchestrators. Different roles and life-cycle management processes are involved in network slicing, with the ETSI MANO framework as an example. However, the security features and mitigation mechanisms apply to any service orchestration framework. Network slices can be composed of multiple lower-level network slices and must meet specified requirements. Confidentiality, data protection, isolation, and encryption methods ensure the security of network slices. Availability requirements are specified, and network slice service profiles define the characteristics and requirements of a network slice. Network slices go through activation, modification, and deactivation phases based on mission objectives and operational conditions.
To ensure secure operations, the document recommends establishing a baseline of security features that support confidentiality, integrity, and availability. It suggests implementing the Zero Trust Architecture (ZTA) methodology and the recommended security features specified by 3GPP standards. Orchestration frameworks like ETSI MANO and ONAP facilitate network slice management, enabling automated design, deployment, and maintenance. Threat vectors such as Denial of Service (DoS) attacks, misconfigurations, and Man-in-the-Middle (MITM) attacks can be mitigated using ZTA principles, authentication, authorization, and audits.
Additionally, the document emphasizes the importance of following cyber hygiene practices, conducting risk assessments, and addressing vulnerabilities. The goals for network slicing include ensuring availability, integrity, and confidentiality, and specific use cases illustrate diverse requirements regarding subscribers, latency, bandwidth, and security. Design criteria focus on network slice service profiles, composition, utilization, implementation variability, isolation, and dedicated resources.
For secure Open RAN deployments, the document recommends ensuring the confidentiality, integrity, and availability of network slice user data within the Open RAN system. Measures such as maintaining the integrity of the physical and logical path of network slice user data, safeguarding the confidentiality of the owner’s identity and geographic location of network slice user data, addressing unauthorized access and misconfiguration compromises, implementing security mechanisms, and following 3GPP security mechanisms are suggested.
Regarding network slicing in 5G devices, the modem-centric approach is recommended, with a transition to an OS-centric approach in the future. Mobile device management (MDM) can be utilized to protect the network slice and the device itself. It is important to securely store NSSAI, implement authentication and authorization for application requests accessing network slices, and ensure cloud and virtualization security controls are in place based on the deployment type.
Various recommendations are also provided for other aspects of network slicing, including network slice creation, deployment, isolation, interconnection between multiple Mobile Network Operators (MNOs), data networking, operations, and maintenance, and the orchestration of network slices. The document encourages compliance with security policies, authentication and authorization requirements, privacy regulations, and adherence to best practices. It highlights the importance of monitoring, management, and ongoing maintenance to ensure the secure and efficient operation of network slices.
By following the suggested measures, stakeholders can ensure the confidentiality, integrity, and availability of network slice operations, ultimately contributing to a secure and robust 5G network environment.
