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Mobile
What is Baseband Processor?
A separate processor in your phone that handles all cellular communication, runs its own proprietary firmware, and has direct access to the microphone and GPS.
The baseband processor is the most privileged and least understood component in your phone. It's a security and privacy black box.
What It Is
- A separate CPU from the main application processor
- Handles all cellular radio communication (calls, texts, data)
- Runs proprietary, closed-source firmware from Qualcomm, Intel, Samsung, or MediaTek
- Has direct memory access (DMA) to the main processor
Privacy Concerns
- Baseband firmware has never been fully audited
- Known to have exploitable vulnerabilities
- Has access to microphone, GPS, and potentially all device memory
- Cannot be disabled while maintaining cellular connectivity
- Theoretically could be remotely activated for surveillance
Mitigation
- Librem 5 (Purism): Hardware kill switches physically disconnect the baseband
- PinePhone: Baseband is on a removable M.2 card
- WiFi-only devices: No baseband processor at all
- Mainstream phones offer no way to isolate or audit the baseband
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