GTP-C Spoofing

In telecommunications, GTP-C Spoofing is the forging of GTP control-plane messages (Create Session Request, Delete Session Request, Modify Bearer) on S5/S8/S11 or N4/N11-equivalent interfaces to hijack subscriber sessions, exhaust bearer resources, or trigger billing anomalies. Mitigation relies on GTP firewalls validating source PLMN, IMSI ranges, and TEID consistency.

Categories: Radio Access NetworkSignalingIdentity and Subscriber

GTP-C Spoofing in context

The radio access network is where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations and downgrade attacks; defenses rest on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

Signaling protocols carry the control-plane messages that set up calls, register subscribers and route SMS. SS7, Diameter, GTP-C and SIP are the four dominant families, and interconnect exposure of any of them is treated by GSMA as top-tier telecom risk.

To place GTP-C Spoofing in the wider telecom-security picture, review OFCS, SUPI Catcher, Cleartext (Plain Text), TCAP Abuse, TEID and UMTS: each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

Related topic hubs

  • GTP Security GTP-C/GTP-U threats across S5/S8, N3/N9 and GRX/IPX borders under GSMA FS.20.
  • GTP Firewall GSMA FS.20 GTP-C/GTP-U screening on GRX/IPX borders.
  • Signaling Firewall Unified SS7/Diameter/GTP/SMS signaling firewall framework.
  • SS7 Firewall GSMA FS.11 category 1/2/3 SS7 message screening at the STP edge.

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.