You can only realistically get into this state if you unlock the bootloader. When you unlock the BL, you’ve voluntarily forfeit warranty (at least for software related issues like this one). I’m 100% sure that if your device bricked after a normal OTA, you’ll get a replacement.
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But those issues would not arise without the counter being incremented in the first place. With unlocked bootloaders, this should be a choice.
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Rollback is disabled before it updates the anti-rollback counter.
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It still hurts custom rom users. I already don't care about my safetynet state, why should I be locked to an android 13 bootloader for security issues that I choose to not care about?
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Rollback protection is part of verified boot. It has existed for the SoC boot chain, secure element and the OS itself for many years. Pixels have used it for the OS and secure element for years. It wasn't used in practice for SoC boot chain due to being a development annoyance.
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An important security feature not being fully implemented due to it being a development annoyance is problematic. GrapheneOS is an aftermarket OS focused on Pixels and we wanted this feature to start being used properly and complained about it not being done on the past devices.
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Not everyone using an aftermarket OS wants to roll back the security model and disable security features. Proper verified boot is a small part of what we expect potential hardware partners to implement. It's not proper verified boot if firmware bypasses aren't fixed like this.
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You're welcome to use something other than GrapheneOS if you don't want the standard security model and hardware-based security features intact. Rollback protection is a basic security feature and has already been used for years, just not for the early SoC boot chain in practice.
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And ultimately, that's why I don't use GrapheneOS.
But it could be a great OS if it didn't insist on denying owners control of their devices, so it's a shame.
It's looking like this case wasn't even a security fix, just DRM.
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Verified boot is an important security feature primarily used to make privileged persistence much more difficult for an attacker. If they can simply write out a vulnerable SoC boot chain, it doesn't work. It's secondarily used for anti-tampering and the same thing applies to it.
This firmware also contains the TEE code. Secure element is separate and has separate rollback protection for itself. Both TEE and secure element are part of providing hardware support to make encryption better, and both the TEE and secure element provide hardware keystores too.
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If you don't have rollback protection, then an attacker can downgrade the TEE and secure element firmware to the oldest published version to have the weakest possible target to attack. TEE is part of SoC firmware and is covered by this SoC rollback protection version.
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Yes, but my security model (for my phone) assumes I always have physical custody of my phone, so verified boot is worthless to me.
I understand and agree it is important to others.
I'm not suggesting taking any of that away from them.
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The primary threat model for verified boot is defending against a remote attacker trying to persist on the device, not physical security. Anti-tampering is a secondary and less important threat model for verified boot. Chromebooks don't really bother even trying to do that part.
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