We can safely assume this has been completely exploited in the field for many years by criminals both inside and outside of government.
And we can also safely assume that anyone motivated enough has been listening in on conversations and taking pictures clandestinely of the conversations of presidents, prime ministers, members of Parliament, senators, representatives and governors.
Not long before some of that information gets leaked publicly or sold on the open market.
As mentioned on Hacker News
The FBI has been tapping mobile phones as "roving bugs" for a decade: http://news.cnet.com/2100-1029-6140191.html
An open and secure baseband SoC/OS is a reasonable project for a well funded startup. I betting there's about to be an eager market.