Denied by Border: Denial-of-Service Attack Exploiting Location Restrictions in Non-Terrestrial Networks

Impact

Denied by Border demonstrates that 3GPP’s integrity protection for 5GMM cause #78 does not eliminate relay-based attacks. The work reveals a remaining design-level vulnerability in NTN location-based access control and validates its impact on commercial NTN-capable smartphones. Following responsible disclosure, GSMA forwarded the issue to 3GPP for further consideration, and discussions with GSMA and device vendors are ongoing regarding the specification and implementation of the observed behavior.