SIP Security 4

Question 1

What does 'media theft' or 'RTP hijacking' involve in a SIP attack scenario?

Accepted Answer

An attacker injects RTP packets to insert themselves into an audio stream

Answer

An attacker steals SIP media credentials for resale

Answer

An attacker blocks RTP packets to silence a call

Answer

An attacker captures SDP offers to learn codec preferences

Question 2

Which RFC defines the SIPS URI scheme that mandates TLS for SIP communications?

Accepted Answer

RFC 3261

Answer

RFC 3310

Answer

RFC 4568

Answer

RFC 5630

Question 3

In SIP Identity (RFC 8224), what cryptographic format is used for the Identity header token?

Accepted Answer

JSON Web Token (JWT)

Answer

X.509 certificate

Answer

PGP signature

Answer

HMAC-SHA256 digest

Question 4

Which threat does the 'Record-Route' header manipulation pose in SIP security?

Accepted Answer

An attacker can insert themselves as a persistent on-path proxy for all in-dialog requests

Answer

An attacker can reroute the initial INVITE to a different destination

Answer

An attacker can prevent BYE messages from terminating a call

Answer

An attacker can modify codec negotiation during the session

Question 5

What is the role of a 'Back-to-Back User Agent' (B2BUA) from a security perspective?

Accepted Answer

It terminates and re-originates SIP calls, providing a security policy enforcement point

Answer

It relays SIP messages transparently without inspecting content

Answer

It provides end-to-end encryption between two UACs

Answer

It authenticates users using certificate-based identity

Question 6

Which SIP attack involves sending a BYE request to terminate an active call between two legitimate parties?

Accepted Answer

BYE teardown attack

Answer

SIP flooding

Answer

Registration hijacking

Answer

Eavesdropping

Question 7

Which mechanism does RFC 4916 define to allow mid-dialog identity updates in SIP?

Accepted Answer

Connected Identity using re-INVITE or UPDATE

Answer

STIR/SHAKEN token refresh

Answer

Digest re-authentication challenges

Answer

TLS renegotiation during active sessions