SS7 Interconnect Security: The Silent Threat

"Analyzing vulnerabilities in Global Title Translation (GTT) and SMS interception."

PopDocs Intel

May 11, 2026

1 MIN

SS7 Interconnect Security

Signaling System No. 7 (SS7) remains the primary protocol for international roaming and SMS delivery, despite its inherent lack of authentication.

1. Location Tracking

By sending a ProvideSubscriberInfo (PSI) request with a spoofed source identity, an attacker can query the current cell ID of any subscriber globally.

2. SMS Interception

The InsertSubscriberData (ISD) message can be misused to redirect SMS traffic to an attacker-controlled HLR (Home Location Register).

Protection Mechanisms:

Signaling Firewalls: Inspecting incoming MAP/CAMEL messages for anomalies.
Diameter Security: Hardening LTE/5G signaling interfaces (S6a, N2).