[ RECORD YEAR ]2017

GTP-C TEID Scanning & GPRS Core Tunnel Hijacking across Roaming IPX

Positive Technologies disclosed critical architectural flaws in GTP (GPRS Tunnelling Protocol) across 2G, 3G, and 4G networks, demonstrating how attackers on IPX roaming networks could hijack subscriber data sessions and execute over-the-air fraud.

THREAT SEVERITY
9.1 / 10
Target TechnologyGPRS Tunnelling Protocol (GTP-C / GTP-U / TS 29.060), IPX Roaming Exchanges, TEID Brute-forcing
OSI Network LayerLayer 4/7 / GPRS Tunnelling Protocol (GTPv1-C / GTPv2-C) over UDP 2123
Threat Actor / AttributionAcademic & Offensive Telecom Security Researchers (Positive Technologies)
Protocol Standard3GPP TS 29.060 (GTPv1) / 3GPP TS 29.274 (GTPv2-C) Specifications

01Video Presentation & Conference Keynote

02Deep-Dive Technical Analysis

GTP control plane (GTP-C) messages traverse inter-operator GPRS Roaming Exchanges (GRX) and IP eXchange (IPX) networks to establish subscriber data tunnels between the Serving GPRS Support Node (SGSN) / Serving Gateway (SGW) and the Gateway GPRS Support Node (GGSN) / Packet Data Network Gateway (PGW). Researchers proved that spoofed `Create PDP Context Request` and `Modify Bearer Request` messages with brute-forced Tunnel Endpoint Identifiers (TEIDs) were accepted by peer operators without cryptographic origin authentication, allowing attackers to hijack subscriber traffic, drain data quotas, or impersonate MNO APNs.

03Vulnerability & Exploit Flow

Exploit Vector

Unauthenticated GTP-C signaling injection across IPX peering points and TEID prediction.

04Recommended Defense & Mitigation Protocol

Operator Hardening Strategy

Deploy GSMA FS.20 compliant GTP firewalls, enforce IPX source IP anti-spoofing, and validate TEID state consistency.

05Security Impact & Geopolitical Consequence

Led to the establishment of GSMA FS.20 (GTP Security Guidelines), mandating GTP-aware stateful carrier firewalls and strict TEID validation on all inter-PLMN S8/Gp/S5 interfaces.

06Authoritative Standards & External References

07Related Topic Cluster Records

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