Case Study: UK Mobile Network Operator strengthens legacy network resilience with NCC Group

From legacy liabilities to mobile network resilience By Philip Marsden

A UK mobile network operator faced significant security challenges within its critical legacy 2G, 3G, and 4G infrastructure. These older networks, which supported essential services like voice and roaming, had uneven security controls, creating visibility gaps and risks of fraud, interception, and service disruption. Recognizing the growing threats to telecommunications, the operator partnered with NCC Group to conduct a telecom-specific security assessment of its legacy environment.

NCC Group implemented a structured Legacy Network Security Testing Programme, which included security assessments of signalling protocols, access model reviews, threat-led testing, and monitoring capability evaluations. This solution provided the operator with a clear, risk-based understanding of its exposure and led to the reduction of high-risk weaknesses, strengthened network segmentation and authentication, and enhanced monitoring visibility. As a result, NCC Group helped the operator significantly reduce the likelihood of a catastrophic compromise, improving the overall resilience of its national mobile services.