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> Are you saying that a phone manufactured in 2022 can have its firmware remotely changed to record microphones? Yes, court records show the FBI has and contin

> Are you saying that a phone manufactured in 2022 can have its firmware remotely changed to record microphones? Yes, court records show the FBI has and continues to explicitly do this. Leaks from folks like Snowden show the NSA/CIA have done this too. > Specifically can your whatsapp/signal audio calls be recorded by FBI remotely in this manner? The baseband firmware is at a level 'below' the operating system of the phone. It can directly access peripherals and intercept them, so it could be reading your microphone and passing it along to the higher level OS at the same time. WhatsApp/Signal thinks it's secure, and if you look at its app signature or anything else it looks exactly like the normal app you expect. However your data is still getting intercepted at the lower level and recorded for a state/government actor.

abdullahkhalids 4y ago
I am not at all familiar with the hardware design of phones, so I want to be very clear in my understanding. Are you saying that the electrical signals from the microphone and to the speakers pass through the baseband chip before/after going to the main chip on the phone? Or that the baseband chip has separate access to the microphone and speakers?
- kube-system 4y ago
  There are varying architectures, so it depends. But at a minimum, the baseband at a minimum has low level access to anything that goes over the network. In some implementations, the baseband can just read straight from main system memory if it wants.
ActorNightly 4y ago
No? Baseband firmware is the firmware for the modem. It has no relation to the SoC that runs the phone, unless there is some sort of exploit that allows it direct hardware/memory access. To listen to the mic or capture video, it has to interface with the ADC chip which is not directly connected to it. There may have been phones in the past that allowed DMA to the SoC from the baseband chip which hypothetically would have allowed a properly crafted exploit on a per app basis, but its not longer the case, as pretty evident by the FBI asking Apple to unlock the phones (if they could access the memory from baseband, they would not need to)
- qbasic_forever 4y ago
  Many phones have the peripherals including microphone connected or accessible to the baseband.
  - TheHappyOddish 4y ago
    Can you provide some examples?

abdullahkhalids 4y ago

I am not at all familiar with the hardware design of phones, so I want to be very clear in my understanding. Are you saying that the electrical signals from the microphone and to the speakers pass through the baseband chip before/after going to the main chip on the phone? Or that the baseband chip has separate access to the microphone and speakers?

kube-system 4y ago
There are varying architectures, so it depends. But at a minimum, the baseband at a minimum has low level access to anything that goes over the network. In some implementations, the baseband can just read straight from main system memory if it wants.

ActorNightly 4y ago

No? Baseband firmware is the firmware for the modem. It has no relation to the SoC that runs the phone, unless there is some sort of exploit that allows it direct hardware/memory access. To listen to the mic or capture video, it has to interface with the ADC chip which is not directly connected to it. There may have been phones in the past that allowed DMA to the SoC from the baseband chip which hypothetically would have allowed a properly crafted exploit on a per app basis, but its not longer the case, as pretty evident by the FBI asking Apple to unlock the phones (if they could access the memory from baseband, they would not need to)

qbasic_forever 4y ago
Many phones have the peripherals including microphone connected or accessible to the baseband.
- TheHappyOddish 4y ago
  Can you provide some examples?