SSCA Security in SIP 4

Question 1

In SIP Digest authentication, the 'algorithm' parameter in the challenge specifies what?

Accepted Answer

The hash algorithm used to compute the response (e.g., MD5, SHA-256)

Answer

The 'algorithm' parameter in the WWW-Authenticate header tells the UAC which hash algorithm (such as MD5 or SHA-256) to use when computing the Digest response.

Question 2

Which attack exploits the fact that SIP uses UDP by sending forged source-address packets to disrupt communications?

Accepted Answer

IP spoofing / source address forgery

Answer

Because UDP lacks connection state, attackers can forge source IP addresses in SIP packets to inject BYE or CANCEL messages to tear down legitimate calls.

Question 3

STIR/SHAKEN is a framework designed to combat which SIP security threat?

Accepted Answer

Caller ID spoofing on telephone networks

Answer

STIR/SHAKEN uses digital signatures to verify that the calling number (Caller ID) matches the actual originating carrier, combating spoofed caller identity.

Question 4

What does 'topology hiding' in SIP security mean?

Accepted Answer

Concealing internal network addresses and infrastructure details from external parties

Answer

Topology hiding removes or replaces internal IP addresses, Via headers, and Route headers so external parties cannot map the internal network.

Question 5

When using TLS for SIP, what does the UAC verify to prevent man-in-the-middle attacks?

Accepted Answer

The server's TLS certificate matches the expected domain

Answer

The UAC must validate the server's TLS certificate against the expected domain name, ensuring the connection is to the legitimate SIP server and not an impersonator.

(SSCA) Sip School Certified Associate Practice Test

(SSCA) Sip School Certified Associate Practice Test

SSCA Security in SIP 4