Burner phones are a strange concept. If you want to store sensitive data on it, you shouldnt use some cheap android phone or even a dumbphone without encryption support.
All Android phones have Google malware installed by default, as system apps, which means those apps can do whatever they want.
So every piece of data you put on there is possibly tracked and collected.
Then there are 2 more problems
the software is proprietary and cannot be externally wiped clean
the software is outdated
This makes it vulnerable to Pegasus attacks and others. There are tons of secure practices to avoid getting it, like LTE-only, HTTPS only, encrypted and trustworthy DNS, sandboxed processes, blocked javascript execution from unknown websites…
But still if the phone is outdated there are unpatched and publicly known security issues. Just spamming them at all phones is likely to succeed as so many people run vulnerable versions, as vendors suck.
Then if you have pegasus, the only way for security is to reflash the A/B partitions, both. Factory reset is not secure as it will keep what is already in the system partitions.
The firmware is protected and signed by the vendors, so it is likely clean.
But Pegasus installs itself to the phone storage.
If you A cant obtain factory images or B cant flash the phone at all, you cannot wipe it clean.
So a good activism phone needs
trustworthy and minimal system apps / stock software
modern software updates
possible to reflash whole device externally
nice to have: ability to verify checksum of system partition, like GrapheneOS Attestation
This makes them poorly pretty expensive. I think a slightly outdated GrapheneOS phone is okay though.
Yes I know, and I want to try DivestOS one time. But they do incomplete patches.
They cannot update the kernel themselves or even worse the firmware. The kernel needs to be built and patched for the specific hardware, GrapheneOS relies completely on Google here. And the firmware needs to be signed by the vendors, so no chance either.
And especially baseband, cellular stuff has extremely many vulnerabilities in the code.
Most of that is solved by installing a ROM that’s not user hostile, keeping it updated of course, and using the phone strictly as a purpose specific device.
That means you run a trusted VPN on it so HTTP/S and DNS concerns go out the window.
Sandboxed processes, blocked JS? Fine if you only install what’s necessary and don’t use the web browser. JS blocking is not a huge hurdle though, ublock does it with just 2 clicks.
Then if you have pegasus, the only way for security is to reflash the A/B partitions, both. Factory reset is not secure as it will keep what is already in the system partitions.
That’s right but I don’t think that this is enough. If the Pegasus malware (package) really is able to do that many things, it’s a walk in the park for it to modify any of the partitions, including that which contains the modem, or just data like the modem’s IMEI and MAC addresses.
In the cause I would either restore a backup of all partitions, or throw the phone away (not literally).
The firmware is protected and signed by the vendors, so it is likely clean.
Except if they patched the verification mechanisms of the OS.
Also, the firmware may be protected, but what about data partitions which are read by vulnerable software.
This makes them poorly pretty expensive. I think a slightly outdated GrapheneOS phone is okay though.
Are you sure? My 6 years old phone still receives LOS updates
Not sure if VPN eliminates all risks with 2G and 3G, maybe it does.
Sandboxing, javascript
Vanadium has sandboxing but its javascript blocking is useless (no granular control)
Mull has no process isolation at all, but support for UBO and Noscript. Bad situation
it’s a walk in the park for it to modify any of the partitions
These cannot be written without TPM verification or stuff, ask GrapheneOS devs about that, I dont know. The firmware signing is required, the verification will not be done inside the OS, that would be totally flawed.
If they have the firmware signing keys, they can fuck you. If they dont, they can only write to the system partition, and Attestation can see that.
Reading data has nothing to do with that. They likely can, but that doesnt matter.
My 6 years old phone still receives LOS updates
This will not include firmware and likely even the kernel.
Not sure if VPN eliminates all risks with 2G and 3G, maybe it does.
It doesn’t, but probably even on modern phones it only does if you explicitly set it to only use 4G but nothing below that.
Mull has no process isolation at all, but support for UBO and Noscript. Bad situation
If you only visit known reputable websites it’s probably not really a problem, but also, I think there are chromium browsers that have addons. Not sure though if there’s one that besides that also has the security patches.
These cannot be written without TPM verification or stuff
I doubt that it couldn’t be written, I believe TPM can only verify its contents and make the phone refuse to boot if it doesn’t agree on the authenticity of the partition contents.
However it’s also a question which partitions are checked that way: only the system partition? Or more? Probably not all, because they can’t verify e.g. the main user data partition, because it’s ever changing contents were never signed by the manufacturer. There’s a few dozens of partitions usually so this is not trivial to answer.
the verification will not be done inside the OS, that would be totally flawed.
Yes, verification is done by one of the bootloaders. At least partly, the OS and maybe other layers must be doing it too, just remember why Magisk had a feature to hide it’s processes and the controlling app itself from select system services and other apps.
Reading data has nothing to do with that. They likely can, but that doesnt matter.
Didn’t mean that. I meant writing data that is later being read by other important system software that is vulnerable to specially crafted quirks in that data.
Not sure but GrapheneOS has an “LTE only” mode, stock Android only has preferred Network afaik.
visiting only known websites is not a scaleable option, a browser needs to be secure. Kiwix is the browser that basically runs desktop Chromium on Android, so it has Addon support. But that is also soon manifest v3 restricted, and likely pretty insecure.
of course the user data partition is not checked, but every other important one. I have not tested what would happen when it is modified though.
I dont know what magisk did, but I think that is only about Google Play adding their “safety” scanning to the OS. Nothing regarding boot. But yes, likely there could, can or should be OS components scanning things too.
Googles stuff is pretty insecure, for example the latest SafetyNetFix simply disabled hardware cryptography, as they still support insecure phones.
For sure this is very complex and there are always vulnerabilities found in Android and GrapheneOS.
The point is not cheapness but that you don’t care about the future of that phone. It’s only a tool for the protest, if it lasts longer that’s good but you expect it to get confiscated and never given back, you don’t care what cops did with it if you get it back, it does not have data you need in your daily life or anything irreplaceable, and you’re not really afraid that it gets destroyed by accident or maliciously.
But what if you get it back? Or if you just keep it?
There is a chance that you have Pegasus on there, and I wouldnt want a phone without the detection of this.
You attempt to flash your full backup to it. And maybe then read it back if you can for verification that it was actually written to memory, but that probably won’t be possible when using fastboot. That’s all you can do that’s reliable, to some extent.
Burner phones are a strange concept. If you want to store sensitive data on it, you shouldnt use some cheap android phone or even a dumbphone without encryption support.
All Androids since 9 at least have been encrypted by default as long as you have a lock screen enabled. Doesn’t matter if its cheap, it is there.
All Android phones have Google malware installed by default, as system apps, which means those apps can do whatever they want.
So every piece of data you put on there is possibly tracked and collected.
Then there are 2 more problems
This makes it vulnerable to Pegasus attacks and others. There are tons of secure practices to avoid getting it, like LTE-only, HTTPS only, encrypted and trustworthy DNS, sandboxed processes, blocked javascript execution from unknown websites…
But still if the phone is outdated there are unpatched and publicly known security issues. Just spamming them at all phones is likely to succeed as so many people run vulnerable versions, as vendors suck.
Then if you have pegasus, the only way for security is to reflash the A/B partitions, both. Factory reset is not secure as it will keep what is already in the system partitions.
The firmware is protected and signed by the vendors, so it is likely clean.
But Pegasus installs itself to the phone storage.
If you A cant obtain factory images or B cant flash the phone at all, you cannot wipe it clean.
So a good activism phone needs
This makes them poorly pretty expensive. I think a slightly outdated GrapheneOS phone is okay though.
Then get a burner pixel 3a and install grapheneOS or DivestOS
I think 3a is already too old. I think 4a is a better minimum, but this is still insecure of course.
https://divestos.org/pages/devices#device-sargo
Yes I know, and I want to try DivestOS one time. But they do incomplete patches.
They cannot update the kernel themselves or even worse the firmware. The kernel needs to be built and patched for the specific hardware, GrapheneOS relies completely on Google here. And the firmware needs to be signed by the vendors, so no chance either.
And especially baseband, cellular stuff has extremely many vulnerabilities in the code.
Most of that is solved by installing a ROM that’s not user hostile, keeping it updated of course, and using the phone strictly as a purpose specific device.
That means you run a trusted VPN on it so HTTP/S and DNS concerns go out the window.
Sandboxed processes, blocked JS? Fine if you only install what’s necessary and don’t use the web browser. JS blocking is not a huge hurdle though, ublock does it with just 2 clicks.
That’s right but I don’t think that this is enough. If the Pegasus malware (package) really is able to do that many things, it’s a walk in the park for it to modify any of the partitions, including that which contains the modem, or just data like the modem’s IMEI and MAC addresses.
In the cause I would either restore a backup of all partitions, or throw the phone away (not literally).
Except if they patched the verification mechanisms of the OS.
Also, the firmware may be protected, but what about data partitions which are read by vulnerable software.
Are you sure? My 6 years old phone still receives LOS updates
Not sure if VPN eliminates all risks with 2G and 3G, maybe it does.
Vanadium has sandboxing but its javascript blocking is useless (no granular control)
Mull has no process isolation at all, but support for UBO and Noscript. Bad situation
These cannot be written without TPM verification or stuff, ask GrapheneOS devs about that, I dont know. The firmware signing is required, the verification will not be done inside the OS, that would be totally flawed.
If they have the firmware signing keys, they can fuck you. If they dont, they can only write to the system partition, and Attestation can see that.
Reading data has nothing to do with that. They likely can, but that doesnt matter.
This will not include firmware and likely even the kernel.
It doesn’t, but probably even on modern phones it only does if you explicitly set it to only use 4G but nothing below that.
If you only visit known reputable websites it’s probably not really a problem, but also, I think there are chromium browsers that have addons. Not sure though if there’s one that besides that also has the security patches.
I doubt that it couldn’t be written, I believe TPM can only verify its contents and make the phone refuse to boot if it doesn’t agree on the authenticity of the partition contents.
However it’s also a question which partitions are checked that way: only the system partition? Or more? Probably not all, because they can’t verify e.g. the main user data partition, because it’s ever changing contents were never signed by the manufacturer. There’s a few dozens of partitions usually so this is not trivial to answer.
Yes, verification is done by one of the bootloaders. At least partly, the OS and maybe other layers must be doing it too, just remember why Magisk had a feature to hide it’s processes and the controlling app itself from select system services and other apps.
Didn’t mean that. I meant writing data that is later being read by other important system software that is vulnerable to specially crafted quirks in that data.
Not sure but GrapheneOS has an “LTE only” mode, stock Android only has preferred Network afaik.
visiting only known websites is not a scaleable option, a browser needs to be secure. Kiwix is the browser that basically runs desktop Chromium on Android, so it has Addon support. But that is also soon manifest v3 restricted, and likely pretty insecure.
of course the user data partition is not checked, but every other important one. I have not tested what would happen when it is modified though.
I dont know what magisk did, but I think that is only about Google Play adding their “safety” scanning to the OS. Nothing regarding boot. But yes, likely there could, can or should be OS components scanning things too.
Googles stuff is pretty insecure, for example the latest SafetyNetFix simply disabled hardware cryptography, as they still support insecure phones.
For sure this is very complex and there are always vulnerabilities found in Android and GrapheneOS.
On the regular day to day use, that’s right. But on a protest you really should be careful, more than usual.
Is that universally true for all phones?
https://grapheneos.org/features#grapheneos
The point is not cheapness but that you don’t care about the future of that phone. It’s only a tool for the protest, if it lasts longer that’s good but you expect it to get confiscated and never given back, you don’t care what cops did with it if you get it back, it does not have data you need in your daily life or anything irreplaceable, and you’re not really afraid that it gets destroyed by accident or maliciously.
Yes that is one definition.
But what if you get it back? Or if you just keep it?
There is a chance that you have Pegasus on there, and I wouldnt want a phone without the detection of this.
GrapheneOS can likely detect pegasus with their Attestation and if you have it, use an external device to reflash it.
You attempt to flash your full backup to it. And maybe then read it back if you can for verification that it was actually written to memory, but that probably won’t be possible when using fastboot. That’s all you can do that’s reliable, to some extent.