CLI Spoofing (Calling Line Identification Spoofing)

An attack where an attacker forges the calling number displayed to the called party. Prevention requires strong CLI authentication in networks (e.g., STIR/SHAKEN).

Categories: Security ControlsThreats and AttacksFraud

CLI Spoofing in context

Security controls span signaling firewalls (SS7/Diameter/GTP screening), transport encryption (IPsec, TLS, PRINS), identity and access on OSS/BSS, and monitoring at both packet and log level. Controls are audited against GSMA FS.11/FS.19/FS.20/FS.36.

Telecom threats range from opportunistic SMS phishing and SIM swap to nation-state grade location tracking. The common thread is that most attacks exploit the inherited trust model of legacy signaling protocols.

To place CLI Spoofing in the wider telecom-security picture, review MAC Filtering, Vishing, A5/0, Artificial Traffic Inflation, ASN and BGP Hijacking — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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