This podcast is an interview with Eric "Musclenerd" McDonald. Eric is a renowned iPhone jailbreaker and as such has a very detailed understanding of smartphone platforms.
His talk at Ruxcon Breakpoint was all about the security of baseband chipsets. If you follow this stuff you might know that the baseband chipsets in these smartphones -- which handle all the basic communications functions of the phones -- are actually quite sophisticated. And where there's sophistication, there are potential problems.
As you'll hear, there's research going into attacking baseband chipsets through two vectors -- directly through the cell network, if you control it, or if you can trick your targets handset into associating with your fake networks... or indeed through the OS. It's interesting stuff.