​​Industry: bridgeOS / checkra1n Questions
​​Enter any questions on the following lines and we will attempt to answer:
​​
  • ​​How easy does this make it to bypass FileVault protections? Does it allow brute-forcing the password or other attacks?
  • ​​What does this mean for SEP-protected ECC keys? Does this allow extracting or cloning the secrets to another device?
  • ​​Does this allow forging the attestation provided for WebAuthN credentials or App Attest?
  • ​​How feasible is it to compromise the T2 directly from macOS instead of via a physical connection?
  • ​​Is this something Apple can firmware patch? Does it affect all T2 chips, or just older versions?
  • ​​Does this make it possible to run an implant or keylogger on the T2 to collect FDE credentials? Was that possible before?
  • ​​Is there a way this attack could be persistent?
  • ​​From @mjc59
  • ​​What can an attacker do with a compromised T2
  • ​​What can an attacker do with a compromised SEP
  • ​​Is there any way for a user to reliably reset their T2 into a known good state
  • ​​Is there any way to detect that this has happened
​​

​​Corrections from ironPeak

  • ​​The T2 is not the SEP, the T2 contains the SEP
  • ​​The boot sequence fully brings up the T2 / bridgeOS before the Intel is released from reset and allowed to boot EFI at all
  • ​​No T2 has SATA, it uses NVMe and PCIe to talk to NAND storage
  • ​​The T2 / bridgeOS is fully booted and stays on even when the computer is off, so the boot sequence holds here for the power button
  • ​​This is not the “next boot disk” since each processor has it’s own system volume, also replace “APFS encryption” with FileVault2 as that is a more accurate term
  • ​​The T2/bridgeOS is charged with approving kexts during load
  • ​​pongoOS is a shim not a replacement
  • ​​Filesystem seals: correctly called SSV (Signed System Volumes) is a iOS 14/Big Sur feature
  • ​​Break SSV and SIP apart
  • ​​Debug cable requires demotion, which is possible with checkm8
  • ​​I suggest leaving out the commands until checkra1n publishes the instructions since you have gaps in it
  • ​​smcutil​ is for older T1 and prior
  • ​​Cannot decrypt FV2, but likely can brute force it (waiting on PoC to confirm that though)
​​

​​Answer Session

  • ​​Have you had an official reponse from Apple
  • ​​Nothing
  • ​​Can checkm8 be done remotely
  • ​​It is a known unknown, no way is known as of today
  • ​​What can an attacker do with a compromised T2
  • ​​Steal computer (iCloud lock)
  • ​​Steal Data (break SEP)
  • ​​Persistent
  • ​​nvram.plist
  • ​​Disable SIP / other protections
  • ​​Non-persistent
  • ​​SecureBoot
  • ​​Keyboard Logging
  • ​​Camera / microphone
  • ​​When lid is closed, electrical cutoff disables these
  • ​​Bluetooth
  • ​​DRAM persistence