UDR (Unified Data Repository)

In telecommunications, the UDR is a 5G Network Function that stores subscription data, policy data, application data, and structured exposure data on behalf of UDM, PCF, and NEF. Access to the UDR is performed through the Nudr service-based interface and is a high-value target for attackers seeking subscriber information.

Categories: Core NetworkIdentity and SubscriberThreats and Attacks

UDR in context

The mobile core carries subscriber sessions, mobility and policy. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF.

Subscriber identifiers (IMSI, SUPI, MSISDN, IMEI) anchor authentication, charging and lawful interception. Any protocol that leaks a permanent identifier is treated as a privacy defect, which is why 5G introduced SUCI concealment on the air interface.

To place UDR in the wider telecom-security picture, review PGW, AMPS, Artificial Traffic Inflation, Backhaul, BTS and Cell Phone (Mobile Phone) — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.