Cell-site simulators (CSS)—also known as IMSI Catchers and Stingrays—are a tool that law enforcement and governments use to track the location of phones, intercept or disrupt communications, spy on foreign governments, or even install malware. Cell-site simulators are also used by criminals to send...
        • 4am@lemm.eeEnglish
          8·
          1 year ago

          Your IMEI, your carrier IP, your packet timing, any DNS your phone leaks, the IP of your VPN endpoint, your transmitter chipset, your likely OS kernel, any unreleased zero-days known to them (and maybe an exploit for them), and also a way to ack TCP packets it never intends to forward in order to sever your connection while letting your device keep taking for as long as possible, which might buy them a little extra time before you realize they’ve captured your session and cut you off.

    • AProfessional@lemmy.worldEnglish
      111·
      1 year ago

      Even that isn’t enough. The wireless modules of normal phones have direct access to system memory and, by law, have proprietary firmware. Some exploits have been found over the years. This needs to be isolated to avoid backdoors/bugs.

        • elderflower@lemmy.worldEnglish
          3·
          1 year ago

          Example: https://grapheneos.org/faq#baseband-isolation

          Yes, the baseband is isolated on all of the officially supported devices. Memory access is partitioned by the IOMMU and limited to internal memory and memory shared by the driver implementations…Earlier generation devices we used to support prior to Pixels had Wi-Fi + Bluetooth implemented on a separate SoC. This was not properly contained by the stock OS and we put substantial work into addressing that problem.

          Baseband modems were not isolated from kernel memory in stock Android, GrapheneOS had to do it themselves using the IOMMU. We do not know for sure due to the proprietary/closed-source nature of baseband modem drivers, but we have no reason to assume any OEM (Samsung, Xiaomi etc) implemented proper isolation of baseband modem and system memory.