VU#615987: Missing IPsec Integrity Protection for IMS SIP Signaling in Verizon VoLTE Deployments (opens in new tab)

Overview VoLTE deployments on Verizon’s IMS network have historically lacked IPsec-based integrity protection for SIP signaling, contravening well-established requirements in 3GPP TS 33.203 and GSMA IR.92. As a result, SIP messages—including registration (REGISTER), call setup (INVITE), and messaging (MESSAGE)—were transmitted in plaintext without cryptographic guarantees of integrity or authenticity. Passive analysis of live traffic over multiple months confirmed the consistent absence of SI...