This is simply a re-application of device fingerprinting and voice verification that many banks are using to secure online banking.

There are many things that can go wrong here, based on my previous experience dealing with these systems, but most require client-side subversion, whether it is malware, cross-site scripting, or cross-site request forgery. (For example, finding a CSRF vuln that allows you to update the phone number to your own and compelling your victim to visit the link through a variety of techniques.)