Sure, there's an extremely well known vulnerability in the iPhone 5C hardware. Lacking the features introduced in later ARM releases it has an unsecured AHB or

Sure, there's an extremely well known vulnerability in the iPhone 5C hardware. Lacking the features introduced in later ARM releases it has an unsecured AHB or AXI bus allowing any device that can connect to perform arbitrary DMA (which can in turn allow arbitrary code execution). It would require a certain degree of technical sophistication to execute that attack, but the resources required would be well within the reach of a state-level investigative service.