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Accidental Google Pixel Lock Screen Bypass

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171–180 of 475 posts

Re: Accidental Google Pixel Lock Screen Bypass

#171
I came across this so called bug. I thought it was a feature. I never realized how it could be used maliciously.

Security is still such a weird concept. Some times it feels like a paralyzing debilitating effort. Similar to how parents yell at you for things you should not be doing, even though it is exciting and useful .

Re: Accidental Google Pixel Lock Screen Bypass

#172
post #156
post #138

Earlier quoted context omitted.

Okay, but fooling a biometrics sensor is not exactly a Lock Screen bypass. Has iOS had a Lock Screen bypass?

Fooling a biometric sensor is precisely a lock screen bypass, that's what the biometrics are for. By that logic the linked bug was "fooling the SIM security layer" and not a "lock screen bypass". Don't play that game, it's bad logic and bad security practice.

But it’s a fundamentally different type of security bug: these biometrics bypasses require knowing something about the user (lift a fingerprint, picture of a face, etc).

I see this as a different class: I can grab an unknown person’s Pixel they left in a coffee shop and get into it.

Re: Accidental Google Pixel Lock Screen Bypass

#173

Earlier quoted context omitted.

It's also a great example why not to use iOS. If you find a hardware flaw in an iPhone and it can't be patched then literally everyone is effected. Even worse is if Apple decides you can no longer use feature/app, it's gone. Fragmentation has it's issues but centralisation is way worse.

except apple takes bug fixes and security 100x more than google does. I remember the Android nightmares of Camera1 Camera2 CameraX APIs, then bluetooth all buggy implementation with years passing by and no decent solution in place. I don't remember a single big bug by iOS

You've invented a quantitative measurement (100x) for something that is qualitative. This unravels discussion and turns away those who may otherwise support your assertion.

Re: Accidental Google Pixel Lock Screen Bypass

#174
post #131
post #89

Earlier quoted context omitted.

Agreed. The fixed logic, at least judging by the commit message, still feels very shaky on correctness grounds ("if we are dismissing something that doesn't seem to be right, ignore it"). Since they're rewriting code and changing method signatures anyway, I would prefer they got rid of the notion of "currently visible screen" and made sure that all dismiss() calls have a unique pointer or token pointing to what exact…

So you'd go out and refactor a major security sensitive component (which dates to time before your career most likely) in a span of a single month for an emergency security patch deadline? That doesn't inspire a lot of confidence in your risk assesment and decision making. I'd do what Google did: rollout a patch that addresses the immediate danger and then backlog proper refactors over time.

I don't think that is as much of an issue as the ridiculous process he had to go through.

Think about that first security researcher. You literally found a Screen Unlock bypass (should be Priority #1, right?) - and Google just went and put fixing it on the backburner.

If they will put something like that on the backburner, what else are they ignoring? It isn't confidence-inspiring.

Edit: Also, knowing Google, what are the odds of your full refactor? "Temporary" fixes become permanent fixes quickly.

Re: Accidental Google Pixel Lock Screen Bypass

#175
post #57
post #43

Earlier quoted context omitted.

The security researchers only mistake was letting Google fart around for so long. You give them 90 days, then you go public. That is the policy Google Project Zero holds other companies to, so it is only fair to hold Google to the same standard. People using their device for high risk applications need to be informed in a timely manner, and Google needs to pay a reputational price for their negligence.

If you use a Pixel for high risk applications you are a bit at fault here

No post body was provided.

Re: Accidental Google Pixel Lock Screen Bypass

#176

Appalling handling on Google’s end here. The duplicate issue part I can understand, but why should it take two reports of a critical vulnerability to take action? Surely when the first one comes through it’s something you jump on, fix and push out ASAP, not give delay to the point where a second user can come along, find the bug, and report it. The refactor that’s mentioned towards the end of the article is great, bu…

You can read in the conversation that Google was not able to reproduce it the first time the bug was submitted:

> The same issue was submitted to our program earlier this year, but we were not able to reproduce the vulnerability. When you submitted your report, we were able to identify and reproduce the issue and began developing a fix.

I wonder if it really was the same bug or what they did wrong to reproduce it. Or maybe they just made some mistake in reproducing it.

Re: Accidental Google Pixel Lock Screen Bypass

#177
post #131

Earlier quoted context omitted.

So you'd go out and refactor a major security sensitive component (which dates to time before your career most likely) in a span of a single month for an emergency security patch deadline? That doesn't inspire a lot of confidence in your risk assesment and decision making. I'd do what Google did: rollout a patch that addresses the immediate danger and then backlog proper refactors over time.

I don't think that is as much of an issue as the ridiculous process he had to go through. Think about that first security researcher. You literally found a Screen Unlock bypass (should be Priority #1, right?) - and Google just went and put fixing it on the backburner. If they will put something like that on the backburner, what else are they ignoring? It isn't confidence-inspiring. Edit: Also, knowing Google, what ar…

> Edit: Also, knowing Google, what are the odds of your full refactor? "Temporary" fixes become permanent fixes quickly.

Hahah, I wish that was only Google :D

Re: Accidental Google Pixel Lock Screen Bypass

#178
post #60

The discussion on race conditions at the end is an important one, and IMO the bugfix is a bandage at best: the notion of anything accessing the “current” object after any kind of delay, especially in an event handler, when there is any chance the thing is not a singleton, is a recipe for disaster. In this case, dismissing the “current” security code screen was a supported API surface and that should set off all the r…

Am I reading this right? This reads like the presence of a UI element holds the unlock state of the phone?

No, not exactly, but Android is old and gnarly enough that a lot of components don't have a clear Model/View separation you'd expect in modern codebases.

Re: Accidental Google Pixel Lock Screen Bypass

#179
post #131
post #89

Earlier quoted context omitted.

Agreed. The fixed logic, at least judging by the commit message, still feels very shaky on correctness grounds ("if we are dismissing something that doesn't seem to be right, ignore it"). Since they're rewriting code and changing method signatures anyway, I would prefer they got rid of the notion of "currently visible screen" and made sure that all dismiss() calls have a unique pointer or token pointing to what exact…

So you'd go out and refactor a major security sensitive component (which dates to time before your career most likely) in a span of a single month for an emergency security patch deadline? That doesn't inspire a lot of confidence in your risk assesment and decision making. I'd do what Google did: rollout a patch that addresses the immediate danger and then backlog proper refactors over time.

Their fix included a similarly large refactor, they just used the "security screen type" as a newly introduced parameter instead of something unique to the screen instance.

I do agree that in the real world, sometimes you have to settle for a less-than-ideal solution. I hope my post reads less like "those people are idiots", which was not my intent, but more like: this specific fix isn't ideal, and knowing this type of code is live in a device doesn't fill me with confidence, even if I can understand reasons for why it was done that way.

Re: Accidental Google Pixel Lock Screen Bypass

#180
post #5

Seems to me like this impacts not only Pixel devices but all Android devices? Patch was to AOSP: https://github.com/aosp-mirror/platform_frameworks_base/comm... I don't have a locked SIM handy, but can someone please test on their non-Pixel device and confirm?

Thing is, most phone manufacturers will customize the lockscreen quite a bit, so it's possible (but not necessary!) it affects others.
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