There's a good practical look into how this works in Martin Vigo's talk.[0] 0: https://media.ccc.de/v/35c3-9383-compromising_online_accounts_by_cracking_voicem

There's a good practical look into how this works in Martin Vigo's talk.[0] 0: https://media.ccc.de/v/35c3-9383-compromising_online_accounts_by_cracking_voicemail_systems https://media.ccc.de/v/35c3-9383-compromising_online_account...