Disabling / removing safetynet entirely - Security Discussion

Apologies if there is another thread dedicated to the topic, but I couldn't find one after some extensive searching.
I've been reading up on Google's "SafetyNet" and quite frankly, it's not something I'm comfortable having on my device. I'm sure I'm not alone on this one.
Since my device can never be compliant (unlocked, rooted, running a third party rom), it provides no value, and represents a fairly large security hole at best. Any services requiring SafetyNet attestation will not work, and I'll have to take my business elsewhere. Way it goes.
I understand that snet is bundled with com.google.android.gms, and I see that I do have the jar and several associated databases; is there an established way to ensure that calls to it are rejected? Has anyone looked into directly removing any of it?

Related

Cydia Substrate — Native (or Java) Runtime Code Modification

Cydia Substrate is a code modification platform. It can modify the code of any major process, whether that code is written in Java or C/C++. It has been designed to support an ecosystem where many developers are interested in hooking the same processes. It is designed to be powerful and efficient.
== How do I get Substrate? ==
You can either download it from the Play Store or directly from its website.
== How do I develop for Substrate? ==
You download its SDK using the Android SDK manager or from its website. There is extensive documentation on the website.
== What is Substrate's website? ==
http://www.cydiasubstrate.com/
== How is this different from Xposed? ==
Many compare it with Xposed, but Xposed only supports a single use case: hooking Java functions inside of app_process. Substrate can hook native code, such as is required to modify the way styles are loaded inside of the Android asset manager. There are many other differences, however, as Substrate's API is based on five years of experience managing a community of runtime code modification for iOS. I normally avoid doing direct comparisons, but after attending Big Android BBQ and presenting on Substrate, I have been encouraged to make the differences and advantages of Substrate's approach more explicit here on XDA.
Xposed requires an inverted form of logic based on "before" or "after" hooks while Substrate lets the developer use more straightforward "replace and call previous" implementations. This also enables more complex interactions with the previous implementation that have been shown to be valuable among the thousands of developers using Substrate on other platforms. Xposed attempts to offer something similar with "replace" hooks, but those do not provide access to the previous implementation, and while Xposed provides a way to call the "original" implementation, that skips any other hooks that might be stacked.
Xposed requires the developer to find a safe moment to interact with the class being hooked. To make this possible, there are numerous lifecycle events such as "VM loaded", "package loaded", and "command line application started". However, this does not solve the problem that touching classes can change the order in which they statically initialize. This also means that it will not be possible to provide declarative syntax wrappers (such as Logos, which developers use on iOS) on top of Xposed, as this context will have to be made implicit in imperative logic. Substrate solves this class initialization problem by allowing developers to hook the classloader itself, getting a callback when a class is "linked" so that the developer can find a class loaded in any classloader (even as a plugin to an application an hour after that application starts, where the code is downloaded as a .dex from the Internet).
Xposed has a method hook implementation that makes it lose track of which method was hooked, requiring it to do a lookup every time such a method is called. This implementation is currently linear in the number of hooks, making it slow down the more hooks you install. Worse, there is a high constant multiplier on this algorithm, as the comparison between entries is very expensive (and was made more expensive when recently fixing a longstanding bug caused by this lookup being slightly incorrect). Substrate, in comparison, uses runtime code generation to avoid the need to every look anything up at runtime: you can use Substrate to hook small functions in tight loops without experiencing the same kind of performance issues you would see with Xposed.
Substrate is also designed with a different user focus: while it currently has a setup interface, it would prefer to not have any UI at all (and this will be strived for in subsequent versions, assuming anyone cares to use it). Upgrades to Substrate can be automatically installed by the Play Store and do not require the user to interact with Substrate for the changes to "stick". Substrate itself is distributed via Play. Rather than confine these kinds of modifications to advanced users who use forums such as XDA, the idea is that everyone should have access to using this kind of technology. If you have a ROM or another store in which you'd like to see Substrate distributed, I would be more than happy to talk to you about this to make that happen, and these installations will be fully supported.
For some more information on the differences between Xposed and Substrate (or if you are wondering why you should bother paying any attention to things that I say, as maybe you don't remember me from my earlier Android projects), I encourage you to read the comments I left a couple posts down from here on this thread that describe the history of Substrate, how I fit into the Android ecosystem, and more about how Substrate differs from Xposed. I will also likely be posting the talk I gave at Big Android BBQ (with either notes to go along with each slide or in the form of a video I will record re-giving the talk and advancing the slides), which might make some of these things more clear.
Current Changelog
[this is the changelog from Play, which has been compressed slightly. I will bring the more full changelog back, as I have it saved somewhere, and put it here or link it here]
v0.9.4011:
* fix decoder bug inside ARM emulator
* support Genymotion Intel emulator
* add symbol names for Moto X
v0.9.4010: critical Android 4.3 fix, avoid old Superuser bug
^^ must install before Android 4.3 OTA!
v0.9.4009: work around Xposed bug, 4.2 fix, better errors
v0.9.4008: HTC linker path patch, limit symbol exports
v0.9.4007: RAZR i 4.1.2, detect HTC override, avoid ps
v0.9.4005: incompatibility detector, avoid mount/ln/mkdir
v0.9.4004: Holo, Script Failure, detect physical /vendor
Comments from Developer
So, yeah: I'm the developer of Cydia Substrate, the framework everyone uses on iOS to do runtime code modification. Back in 2011, I gave a talk at Android Open along with a demo of Substrate running on Android 3.0. However, after some in-depth discussions with people there who were interested, I realized that what I had at the time "wasn't sufficient": it was just the core of an implementation, not an end-to-end offering. By the time it had everything I felt it needed to launch--including a comprehensive website filled with documentation, a configuration application to install with it, fully tested support for both ARM and x86, a forward-compatible pure Java API vetted by a bunch of the top people in the iOS modding community (as I feel like breaking APIs after launch is one of the more evil things a framework can do), and an extension that would make sense to end users that they could try (so that trade press wouldn't be horribly confused, as I knew they would report on the release)--it was already 2013.
http://www.youtube.com/watch?v=tA9cnemnQ0A <- Android Open 2011 keynote teaser
As many people then know, I released it in June. A lot of people have tried it (165k installs just from Play, and another 20k downloads of the APK off the site), and many of those people even like it enough to keep it installed and leave positive reviews, despite there being almost nothing available to use with it except WinterBoard (which I really only did as a demonstration). However, I also get comments from people who seem to believe I'm some kind of "interloper" in the world of Android. Additionally, there are the people who leave reviews saying stuff like "this is stupid, we already have Xposed" (sometimes then explicitly adding in the "go home to iOS" kind of spiel). The #1 complaint, however, is "nothing I can do with it", because developers never seem to talk about it or use it much, and the people installing it are all end users. Clearly this isn't the kind of reaction that I thought would happen, especially after having discussed Substrate at length with pulser_g2 before launch (who said that the community here tends to be very good about judging things on their usefulness and technical merits as opposed to having emotional attachments).
http://www.cydiasubstrate.com/ <- Cydia Substrate
Given this, and after an encouraging back/forth I had with some people on reddit's Android subreddit a few days ago in some threads about the analysis I did of that recent Android iMessage client (people who didn't know much about the ways in which Substrate is very different than Xposed in capability and focus), I figured I'd finally make a post on XDA. I kind of had been waiting to make this post as well, honestly (as again: I like things to be more perfect before I release them than maybe people are used to around here ;P), but it seems like I'm now waiting for something that is itself causing the delay (I had really expected to do this in July, before the whole thing got more actively depressing). This is clearly that post ;P. I've responded to a bunch of other threads here talking about Substrate (and the many other Android projects I've released) in the past, but this is the first time I've actually started a thread.
(In specific, Substrate currently doesn't support some Samsung devices due to a change they make to the linker paths, and I wanted to have 100% device coverage before making the inaugural XDA post. However, I'm finding it very demotivating to spend the time to think through all the options I've been considering for workarounds given the overall lackluster reaction to my work, so I'm not even making fast progress anymore: I tend to work on the things that people react positively to, and while I got a lot of positive reactions on the balance from users, I got much less than I expected from developers given how many people use Substrate on iOS and how powerful the framework is. I think, from some conversations I've had, this is largely due to confusion over how Substrate on Android relates to Xposed, which many people seem to think of as the "home-town competitor" "that does the same thing". I thereby figure that I may as well attempt to directly address that core motivation problem, to see if I should even bother continuing spending time helping out in this community, hence this ludicrously long and highly personal post about what is essentially a technical framework ;P.)
[Readers who find the next section boring should skip below to "=== Substrate ===".]
I imagine I (sadly) thereby need to start by defending my history in the Android community, as many people seem to not be aware of much of it; it actually goes back very far, as I had promised the overall mobile community that if Android were ever rooted, I'd immediately start looking at it in earnest (before there was a device, I had already been messing around with the emulator, but the device concepts Google had at the time were more like slightly souped-up feature phones, not competitors to something like an iPhone). So, in 2008, when that first "root console attached to keyboard" mistake was found on the G1 that let you get a root telnetd running by just typing it into any search field, I dropped everything and drove two hours to Los Angeles to pick up a G1 (they were not selling them in Santa Barbara yet, due to T-Mobile not really having a presence here at the time). As promised, I immediately set to work attempting to help out.
As I ran a number of mailing lists already for iOS, I set one up for Android called g1-hackers, which attracted a good number of people, and even a few Google employees who worked on bionic and the kernel. On this list is where the G1's bootloader was first dumped: if you've ever heard the stories about Eddie Dost figuring out how to do it, this is that. In fact, it was from my G1, with a kernel I compiled (following Eddie's direction: I did not know much about flash drivers), that that first Android NAND was obtained (as Eddie had already updated his device and thereby didn't actually have root). Here is a link to the mailing list thread, directly to the post where we finally succeeded and I provided the kernel image I used so that others could perform the same dump on their own devices.
http://www.telesphoreo.org/pipermail/g1-hackers/2008-December/000096.html <- [g1-hackers] G1 boot code
Around that same time, I was also contributing to AOSP, providing a bunch of patches to things like mount and init, as I wanted to be able to get Android devices to a state where they could run something much closer to Debian than Android (I had my eyes set on kind of a hybrid). In the process of doing this, I wrote a guide that for a couple years subsequent were the canonical instructions for getting a bootstrapped build of Debian installed as a chroot under Android. At the time the patch turnaround on AOSP was sometimes over half a year (and almost never shorter than a couple months), which made contributing to the project sufficiently painful that I eventually stopped. If you search through Android's codebase, though, you still find some of my work.
http://www.saurik.com/id/10 <- Debian & Android Together on G1
At the time, I honestly do not remember XDA having yet become "the place" where people spent much time talking about Android: instead, a lot of conversation happened on IRC (which is where the iOS community had already been, and where it remains). There was a channel that I was a part of which included a bunch of people whose names would hopefully be familiar to people around here, including JesusFreke (and, much later, Cyanogen). I got to see the birth of a lot of great websites and tools (such as JesusFreke's smali/baksmali) while participating on that channel. Apparently, I was talking about "Substrate for Dalvik" on that channel in November of 2008 (which is also when I first joined XDA): that's how long I've been staring at this ;P.
During the next couple years, I ended up developing and maintaining a website called Cyrket, which had the mission to allow developers and users to search the contents of the Android Market using their desktop web browser. It also solved a few key problems that developers had with comments, in that you could only see comments for apps your device had access to that were then written in your language. Developers without devices, or with devices that could not see their product (which often included those that paid extra for the ADP1, which could not see copy-protected apps) could not see comments at all. Cyrket presented all of the comments for your application in all regions in all languages (and even used Google Translate to translate them all into your own language).
The way Cyrket had worked is that I scraped the contents of the Market using the same protocol Google's client used, indexed it (supporting find-as-you-type search), and exported it all to the site (well, originally, it was actually just a live client, but then it got really popular ;P). It got me into some mild trouble occasionally with the Android Market team, but overall no one seemed to mind it that much. Cyrket was actually the primary site people used for this purpose for a long time, and I even got the impression that people at Google were begrudgingly using it as it was more convenient than the alternatives. There were a few times where it had to be taken offline (due to changes and rate limits from Google), one time for months, but I'd usually figure out some new way to get it running. Honestly, though: I was really glad when Google finally launched a website for the Market and I was able to stop working on Cyrket ;P (and also glad that Google added most of Cyrket's features for developers to their publishing console, features that Apple actually still doesn't have AFAIK).
http://www.androidtapp.com/cyrket-android-market-browser-back-from-awol/ <- Cyrket Android Market Browser Back from AWOL!
Since those times, I mostly felt the need to get Substrate "awesome" (which started to really come together during 2011, after Cyrket was no longer needed), and so didn't do many larger projects on Android until recently. That said, I have been involved in things related to exploits and security. One of the higher impact things that I did was to release mempodroid, an implementation of the mempodipper exploit described by Jason A. Donenfeld for Linux 2.6.39+, which became the primary method to root devices running Android versions 4.0.0 through 4.0.2. Much more recently, users have been using Impactor, my implementation of the various "Master Key" exploits (based both on bugs described by Jeff Forristal as well as techniques I pioneered against a random AOSP bug).
https://github.com/saurik/mempodroid <- mempodroid README
http://www.saurik.com/id/17 <- Exploit (& Fix) Android "Master Key"
Given all of this, I hope people can get a feeling for just how strange and depressing it feels to me when people seem to suddenly believe I'm some kind of foreign invader . (FWIW, I also feel rather awkward having to describe all of this in this fashion, but frankly I'm at a point where I'm realizing that if I don't explain it in this much detail myself, no one else will. While I'm certain I'll get some people responding really negatively with comments like "he's such a blowhard, going on and on about silly little things he did", so far when I've given similar spiels to people in person at conferences, they often go "oh wow, I remember that tool/happening, but didn't remember that that was also you", and so figure that this might go a long way to fixing this weird problem: I'm not just "that iOS jailbreak guy".)
=== Substrate ===
Alright, now with that aside: in time for Google I/O (which was arguably bad timing, as I was then immediately unavailable for days ;P), I finally released Substrate. Substrate (in my clearly biased opinion ;P) is actually really cool: as far as I know, it is currently the only tool available for Android that allows developers to easily modify native code without patching/replacing. I know, for example, that people often ask how to modify features like the holo themes that are implemented in C, and the answer is Substrate: if you can find the code (which is often exposed via a symbol as there are tons of C++ symbols available on most Android builds) you can use Substrate to hook it at runtime in a way that avoids having to patch the files on disk, allows developers to deploy their changes across multiple ROMs, and supports the idea that users should be in charge of the specific features that they have on their devices (as opposed to ROM distributions).
As another concrete example that maybe makes this more obvious: sometimes you download a program from the Play Store (which, incidentally, I have a very hard time not constantly still calling the Android Market ;P) that is pretty much just a massive JNI binary--maybe an OpenGL game or a media player of some sort--that refuses to run on a device that has been rooted. A really common way that developers implement such checks is to do things like verify the existence of files on disk. The simple/common checks are very easy to detect and defeat using Substrate as you can hook the native "open" call from the C standard library, check if the filename is something like /system/xbin/su, and return "nope, not there".
http://www.cydiasubstrate.com/api/c/MSHookFunction/ <- MSHookFunction()
Substrate lets you do this kind of hooking in any system daemon (not just those spawed via app_process). Yes: if there's a program running in the background of your phone, some native service written by the OEM that manufactured the device, you can use Substrate to modify it. A lot of very interesting extensions on iOS involve these kinds of hack; for an extreme example, the software unlocks that we used to have for earlier iPhones involved modifying CommCenter, a native program that initializes the radio hardware: by hooking some of the code in that daemon, it was possible to, at just the right moment, inject a different command sequence over the serial connection to the baseband, exploiting it for the unlock.
http://www.cydiasubstrate.com/inject/android/ <- Android Native Injection
Of course, Substrate also supports hooking Java code (yes, a little like Xposed, which at some level uses the same underlying trick I walked people through in my talk at Android Open 2011). Somehow, though, a lot of developers don't seem to catch all that other stuff that Substrate lets you do, and get hung up on this one part that Xposed also manages, leading to all those aforementioned irritating comments about how "there's no point to Substrate because we already have Xposed": Xposed can't do most of the things Substrate can do (and the developer has even told me that he actively tries to avoid Substrate-like techniques as they are "pretty complicated", so it isn't even moving in that direction). FWIW, on iOS it took a lot of time for Substrate to get these features (it did not have them in 2008 when I first released it): they aren't trivial ;P.
http://www.cydiasubstrate.com/api/java/MS.hookMethod/ <- MS.hookMethod()
Even within the restricted context of modifications to Java, however, I think Substrate has a lot to offer. Again: I actively refused to release Substrate until I felt I had truly nailed a few things, including in particular the Java API (at Android Open 2011, I only supported JNI, which developers there told me would not lead to traction). I was a major proponent of aspect-oriented programming when I was younger, I got into byte-code engineering in college, and I co-published a paper on a Java code modification framework called jMonitor in 2004: this is something I've been thinking about for a long time, and I think the approach I take has some merit in and of itself. I know a lot more can be done (I feel it would be really interesting to have AspectJ-style pointcuts, for example, or the kind of bytecode-level instruction matching that I implemented as part of jMonitor <- features not described in the paper, I think ;P), but I felt a good first step was be to directly leverage the iOS community's six years of experience.
http://www.cydiasubstrate.com/id/6dfa187d-6e04-4f97-b63a-ae75b5338e01/ <- jMonitor [RV '04]
To this end, Substrate provides an API for Java that is very analogous to the API that it provides for modifying C/C++ and Objective-C. The focus is on "I know about some code and I want to modify it", allowing you to not have to think much about the timing or execution details of the program that may be loading that code (so you never have to think about "packages" or "processes" or "applications": you just concentrate on "classes", and thereby don't need a million "helper APIs" to handle each narrow timing case). To enable this, I use the aforementioned ability of Substrate to modify native code to hack features into the VM itself, giving me the ability to instrument events like "a class has been loaded". If you want to hook a method of a class from Apache Commons, and you want to hook that class no matter whether it was loaded as part of an application or dynamically as part of a classloader for a plugin downloaded by an application, this is trivial to express with Substrate. AFAIK, that use case isn't even describable using Xposed.
http://www.cydiasubstrate.com/api/java/MS.hookClassLoad/ <- MS.hookClassLoad()
This kind of VM-level modification and runtime code generation support (that is heavily flexed on iOS Substrate, and thereby has had years of in-the-field testing; so far Android has exposed just one bug in its ARM reassembler after release, and that was only in the qemu emulator for some reason) also means that Substrate's implementation of hooks is highly efficient: to compare again to Xposed, every time a method that has been hooked is called via Xposed, there is a linear-time search through a linked list doing a rather heavyweight comparison to determine which method it was after the fact; with Substrate, every call is direct, there are no lookups, and there are no comparisons, so you can hook an arbitrary number of methods with no slow down, so even very small methods that are called very often can be hooked without issue.
Additionally, with Substrate I wanted to address a specific pain point that many people would bring up when I'd give talks: "how is this secure, and how do I control what apps can use these features". This became even more important, as I wanted Substrate extensions on Android to be easily deployable via conventional means, such as the Play Store (yes: Cydia Substrate itself is in the Play Store, as I believe it is important for these kinds of features to not just be in the hands of developers on forums, but to be used by end users everywhere). To this end, I integrate into the Android security model, providing a special permission that applications must have to install a Substrate extension. This helps enable the idea that Substrate mostly "gets out of the way", becoming more of a technical detail behind your extension rather than something users will need to interact with constantly to activate or update your product.
I also wanted to provide at least something that would help solve the "reflection hell" that developers seem to always find themselves in while attempting to do runtime code modification in Java (even back on desktop Java using AspectJ). I thereby provide the means to "bless" a class loader, allowing it to access private fields and classes without the overhead of reflection: the access checks, for just that one class loader, no longer apply. Substrate extensions are loaded into such a "blessed" classloader. (I do not, even though I could, ever just whack an access check VM-wide; Xposed does this, and I feel like it is going to have security implications on Java security contexts applied to class loaders for plugins.) In the case of WinterBoard, for example, I don't ever have to deal with invoking Methods or getting Fields: setAccessible is just a dim memory.
Being able to use this functionality, however, can be awkward, and in some cases is almost impossible: while testing this feature, I realized that developers would end up needing "public stubs" for all the classes they were working with, but the calling convention for a public method and a private one is different, so the calls fail at runtime. I thereby ship as part of the Substrate SDK (yes, there's an easily-updated SDK package that you can download using the Android SDK Manager ;P) an extension to javac itself (as you might imagine at this point, written using AspectJ) that turns off access control checks: you can thereby access private fields or call private methods with no extra work both during development and at runtime. This all works sufficiently well that I generally run all of ant under the modification, such that anything ant compiles becomes "blessed".
http://www.cydiasubstrate.com/id/c17c554f-b603-4e3b-8f99-ebb3528e3ef8/ <- Java Access Controls
(And yes: this is one of the things that caused Substrate to get delayed even longer than it already had been. There was also a rather serious delay caused by my attempts to really nail the boundary between "code that is shipped with Substrate" and "code that is shipped with the extension", something that burned me a lot throughout 2013 as it was the kind of problem that spending time actively thinking about didn't directly help, requiring an epiphany I had soon before Google I/O. Arguably had I been willing to ship without documentation at all, and had I generally cared less, I would probably have had everything out in very early 2012, but during January-May I started working on the initial draft of cydiasubstrate.com, as I had apparently incorrectly thought that such efforts would be critical to developer adoption.)
Again, I write this in the hope that it clears up misconceptions, either about myself or about Substrate. As far as I can tell, Substrate has a lot of very unique value propositions: things that currently are only made possible by Substrate; and, even within the restricted scope of hooking Java code inside of a service being managed by Zygote (the only area of overlap with Xposed), I think that it offers a bunch of advantages in security, performance, deployment, and ease of development that cannot be so casually dismissed with a flippant "we already have Xposed (go home)". A lot of these features (and I haven't even gone into all of them: I could write paragraphs about the advantages of how Substrate's API handles chained hooks, the ways I enable extensions that need to cross classloader boundaries, or the way Substrate makes it easy for end users to temporarily disable extensions without complex tooling) come from having spent over a decade now thinking about this problem and the last five years actively managing a developer ecosystem with tens of millions of users on iOS.
I am thereby happy to answer any questions about how to use Substrate, issues with Substrate on any device (I never blame the device: I might not have a fix immediately for a specific problem, but I always consider it Substrate's job to work around issues the device throws at it to get its functionality in place so the task will at least end up on my todo list), or even about me (as a lot of why I find writing this both so important and so painful are due to the occasional-yet-present more-personal attacks/misconceptions I often seem to receive about somehow being an "outsider"). (That said, please do have some patience: sometimes my ravenous need to do nearly 24/7 testing on a specific device has to give way so I can go to a conference I'm giving a talk at, or so I can focus on a different problem that might be more pressing or simply have a higher probability of near-term success: spending an infinite amount of time on one problem is unfair to all of the other problems that exist ;P.) [And, in fact, I have a meeting I have to be at tonight, but which hopefully won't take insanely long.]
Reserved Post
["reserved", as apparently you always should have at least one of these ;P]
Links to Extension Threads
[and finally, I can see ending up with a page that might link to other threads on XDA, although arguably I should put this on cydiasubstrate.com. right now, most projects that use Substrate are in Play. I am not certain if I'm now just misunderstanding how to use XDA, though: again, this is my first thread I've started myself]
Wow. The timing couldn't be any more perfect for you to post this.
I do not have an Android device yet and have been theorizing exactly how I could easily make modifications to applications.
Because I am just getting started in the Android development community, I don't have any biases towards one framework or the other.
Sooo.... this is on my watch list.
gugbot said:
Wow. The timing couldn't be any more perfect for you to post this.
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The opinion of many (reasonable) people differ ;P.
gugbot said:
Sooo.... this is on my watch list.
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Yay! If you have a moment, I'm curious: how/why did you find this thread? It seems like very few people actually go to this "Frameworks" sub-forum; there are almost no threads posted to it except the one about Xposed, which I'm presuming people must be finding by links from other places (whether random websites or other threads on XDA).
saurik said:
The opinion of many (reasonable) people differ ;P.
Yay! If you have a moment, I'm curious: how/why did you find this thread? It seems like very few people actually go to this "Frameworks" sub-forum; there are almost no threads posted to it except the one about Xposed, which I'm presuming people must be finding by links from other places (whether random websites or other threads on XDA).
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I was browsing in development tools and was surprised to see that a Saurik posted about Cydia Substrate!
I was brought to this forum by one about theme development?... Maybe you should post this in a forum with more traffic. There seems to be an endless amount of categories for everything.
i have try your cydia substrate on cm10.1.3 stable..device samsung i9300..
install winterboard..apply icon pack but icon pack not applied..
then when want to open other apps the apps fc..except winterboard..
slipar said:
i have try your cydia substrate on cm10.1.3 stable..device samsung i9300..
install winterboard..apply icon pack but icon pack not applied..
then when want to open other apps the apps fc..except winterboard..
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Yeah, as I mention in this thread WinterBoard was more of a demo that has been difficult to justify improvements to . This isn't an issue with Substrate, at least.
Would you mind sending me the crash report from the adb log? At least, would you mind telling me the name of the theme you applied? Also, thinking about it, CyanogenMod already has a theme engine... it never occurred to me how WinterBoard would interact with the existing theme engine in CyanogenMod (although I guess thinking even longer about it, I see no reason why it would fail horribly... it should just layer on top).
saurik said:
Yeah, as I mention in this thread WinterBoard was more of a demo that has been difficult to justify improvements to . This isn't an issue with Substrate, at least.
Would you mind sending me the crash report from the adb log? At least, would you mind telling me the name of the theme you applied? Also, thinking about it, CyanogenMod already has a theme engine... it never occurred to me how WinterBoard would interact with the existing theme engine in CyanogenMod (although I guess thinking even longer about it, I see no reason why it would fail horribly... it should just layer on top).
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hope i send u the correct logcat..
im using ios7 concept theme..g play link here
slipar said:
hope i send u the correct logcat..
im using ios7 concept theme..g play link here
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Thank you so much for the information. Here is a new version of WinterBoard that seems to work with this theme.
http://cache.saurik.com/apks/com.saurik.winterboard_0.9.3922.apk
thanx saurik..tested but this time winterboard just fc when try to change theme..
logcat attach..
slipar said:
thanx saurik..tested but this time winterboard just fc when try to change theme..
logcat attach..
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Click to collapse
I'm sorry about that issue... this is actually quite interesting to me as it might indicate that I need to do some more work on the blessed compiler as it relates to miranda methods. I had verified that the theme functioned, but had not gone back to attempt to re-verify the setup activity itself, which I guess hadn't been recompiled in a long time. I've added a temporary workaround to the issue while I investigate further. ("Humorously", if you have Xposed installed, I am pretty certain that the WinterBoard settings activity would have worked, as Xposed just destroys the access control checks for the entire VM.)
http://test.saurik.com/xda/com.saurik.winterboard_0.9.3922+1.gf733f01.apk
Hey there, I just happened upon this thread while deeply perusing the boards after just getting home from a 17hr drive and being unable to go to sleep yet. I am VERY interested in the substrates capabilities, it sounds like a very interesting concept. I am a new developer and am wanting to learn more and play more....I use xposed on my phone now and was considering starting to develop modules for it, buuuttt I think I just changed my mind I'm on an att sgs4 running a 4.3ge Rom. Going to install the substrate the night via Play Store and mess around with it starting tomorrow. Thanks for this
Sent from my GT-I9505G using Tapatalk
Sc4ryB3ar said:
I'm on an att sgs4 running a 4.3ge Rom. Going to install the substrate the night via Play Store and mess around with it starting tomorrow. Thanks for this
Click to expand...
Click to collapse
Yay! (Now, watch your GT-I9505G be one of those few Samsung devices Substrate detects as incompatible ;P. Samsung has so many model numbers that all map to the same high-level marketing names that it's difficult to keep track of what's what. If that happens, and you are interested in helping out, I can implement one of my alternative injectors quickly for you to work with.)
saurik said:
Yay! (Now, watch your GT-I9505G be one of those few Samsung devices Substrate detects as incompatible ;P. Samsung has so many model numbers that all map to the same high-level marketing names that it's difficult to keep track of what's what. If that happens, and you are interested in helping out, I can implement one of my alternative injectors quickly for you to work with.)
Click to expand...
Click to collapse
It installed just fine, quickly and with no apparent issues
winterboard, however rendered neither theme I chose correctly, wondering if its the themes though.... Didn't get a logcat and then I hosed my system last night messing around too much, so I started fresh and haven't gotten back to substrate and wb yet....I'll be back to it withing a couple of hours
Sent from my GT-I9505G using Tapatalk
substrate source code
Saurik,
I've been dabbling some with Cydia Substrate and it seems to offer a lot of unique possibilities for Android apps.
Do you have any plans to release the source code for this like you did on iOS? I'd be very curious to learn more about how it works. Also, is there a link to your talk from the Android Open conference?
Thanks,
Fred
(Ugh. I have no clue how people keep up with a forum, especially with the website as slow to load every page as it is ;P.)
fjones8856 said:
Do you have any plans to release the source code for this like you did on iOS? I'd be very curious to learn more about how it works.
Click to expand...
Click to collapse
I currently do have an intention to release the source code, but I'm not certain under what license (all of the licenses I normally use don't solve the specific issues related to Substrate). That said, no one seems to care much about Substrate on Android: on iOS people tend to (almost to a level of it being a problem) jump on new solutions to evaluate constantly, whereas on Android people seem to just snark "we already have X" even when there are compelling advantages to a replacement. Given this situation, I am highly unmotivated to spend the time to figure out the right solution, given that in a way Substrate is "my magnum opus": it is the culmination of the research and experience of so many years of my life, that passing up the ability to license it to the companies that sometimes talk to me about that (for either enterprise wrapping or security) to satisfy a group of people who are mostly asking for the source code specifically to replicate the technique *and then avoid using Substrate*, makes very little sense.
On the project side of it, Substrate on iOS only ever received a single code contribution from someone I wasn't already so close with that I was sharing code already. It isn't even the kind of project that one would expect getting many contributions: it is more of a backend technology, and the extent to which it has a GUI is actually a bug (I intend for it to be 100% seamless as part apps that use it: Substrate on iOS does not have a GUI and never will have a GUI, and that's how I think it really should work on Android as well, but of course right now I need the silly Install button). If anything, on iOS, we often end up with random companies that want to "own the scene", which ends up with them forking Substrate in ways that cause platform incompatibilities for other developers: Substrate on iOS has thereby actually been closed source now for almost two years, and it has actually improved the stability of the platform. I thereby am somewhat loath to "repeat the same mistakes from before" and end up with forks.
fjones8856 said:
Also, is there a link to your talk from the Android Open conference?
Click to expand...
Click to collapse
There was no recording of the actual talk, just of the keynote introduction that I already link to from my website. In the talk I walked people through a demonstration of using an early version of the JNI-level Substrate API, and showed how it worked (which was very simple at the time). In essence, I demonstrated, with my exact code on the projection, the technique that Xposed started using half a year later (which is just "oh, I'll change the contents of this Method object, as apparently the runtime doesn't care if the Method is allocated as part of a Class; if I do it right I can simulate registerNatives") and the most obvious way of implementing MSJavaHookClassLoad (which--for the really really low-level API I had at the time, on pre-4.0 VMs that didn't have complex JNI stacks--is clearly "MSHookFunction the class load and provide a callback"). Everything is going to be new for ART, though: the techniques are going to have to be much more sophisticated (which I'm excited by, as this is a game changer).
Pm sent
Sent from my GT-I9505G using Tapatalk

Serious, unpatched vulnerabilities

Before I begin, I'm not here to flame tbe devs as I would love this app if these issues weren't present and do hope this problem is resolved as a result of bringing it to the attention of the community and hopefully this app's devs.
This application has serious vulnerabilities, some of which should be quite easily patched yet have not been for months to a year or so of them having been made public by a reputable security researcher working for Zimperium.
Login information via the browser is not utilizing a secure form of encryption for both web.airdroid.com or when accessing via local IP despite their SSL cert being valid for *.airdroid.com. The key for the DES encryption being used to hash the password and e-mail being hardcoded into the application despite having a POC for an attack on their users is inexcusable and shows a blatant disregard for their application's level of access as well as their user's safety and security.
My finding (as a security noob) has also deeply disturbed me following no response to bug reports or email contact. While attempting to check out their Windows desktop client, my antivirus discovered the installer attempting to download a variant of adware which monitored the user's activities and provides monetary incentives to developers which include it within their programs and applications. I do understand that if something is free, the product is you. However, I am a paying customer of this service as I'm sure many who use xda would be in an effort to support development of software and applications we enjoy. This adware was ran through and confirmed with VirusTotal and certainly is not a false positive. This desktop client also does not use SSL for communication.
Due to discovering these problems, I immediately discontinued use (the same day I renewed my yearly subscription). However, I was unable to remove the application from my phone without a full factory reset even after both application updates and upgrading android versions. With it set as a device administrator, it's access must first be revoked before uninstalling. However, across multiple devices and versions of android, attempting to remove it from device administrators causes a crash of the android settings app.
I had planned to do a POC for what I feel is an extremely likely scenario based off both public vulnerabilities as well as what I had discovered myself, but I have been far too busy with a few other projects as well as work to complete it yet. I had just stumbled across this section of the xda forums while looking for something else and hoped to get a response from the devs of this app.
I would love to be able to utilize an app with this functionality. However, there needs to be far more focus on security in its design before I would ever feel comfortable utilizing it again.
In theory, it would be entirely possible for an unstable, technically inclined person at a local coffee shop (or other public location with unsecured an wireless network) to hijack a user's login information with minimal skill level required then giving them full, unadulterated access to the application's functions such as forcing gps or camera on to track or watch someone without their consent as all connections aren't even requiring the user to accept the incoming connection on their phone to perform these actions. That is not a farfetched scenario and presents a possible threat to someone's physical safety.
Link to said researcher's findings can be found on his blog by searching Zimperium airdroid multiple vulnerabilities as I just created this account for this post and can not yet post outside links.
Thanks a lot for all this information. I really appreciate it.
Why hasn't this been addressed yet?
I remember reading this a while ago, realizing that it is a serious issue, and just how little the devs care about security on their app.
This is mainly because most end-users don't dive this deep into an app, and don't fully comprehend the severity of such vulnerabilities until it is too late.
We should make a bigger fuss about these things!
I've always been very careful with RAT-type apps and so I was when checking out AirDroid. I've uninstalled it after 30 minutes of using, just because I didn't like the fact, there's a chance some undesirable person could start spying on me. As I read this thread, I'm realising how right I was that time.

Remote Code Execution in media framework. Severity: critical

From https://source.android.com/security/bulletin/2017-12-01 --
The most severe vulnerability in this section could enable a remote attacker using a specially crafted file to execute arbitrary code within the context of a privileged process.
Thoughts on this one, guys?
Any possibility this could be mitigated somehow, short of tossing the Android device in the trash and buying an iPhone instead?
In particular, is there any way to just disable the mediaserver or whatever altogether? It would be much better to not be able to play videos, than the possibility of any video pwning your entire device, no?
Vulnerabilities like these are patched almost every month (just have a look at the bulletins of the months before), so this one doesn't seem any worse than those that have been there before. To the best of my knowledge, neither of these have ever been exploited in the wild - not even Stagefright back in 2015, according to Google: https://www.theregister.co.uk/2017/02/15/google_stagefright_android_bug_zero_success/
Note that the security bulletin you linked to also states the following:
"The severity assessment is based on the effect that exploiting the vulnerability would possibly have on an affected device, assuming the platform and service mitigations are turned off for development purposes or if successfully bypassed."
Click to expand...
Click to collapse
I hope they can't be bypassed too easily...
What I don't understand is what 'privileged' means here. Does it mean 'root' or does it relate to Android app permissions? The former sounds much worse, and I'd find it alarming if the media framework stuff would (still) run as root (or something similar). Would be great if someone could clarify this.
As I tend to be kinda paranoid when it comes to computer security, I'm also always worried by issues like these, but my impression is it's probably something we have to live with :-/
In particular, I don't see a reason to believe the iPhone is more secure (apart from the fact that it receives regular updates in contrast to most Android phones...)
One would probably be better off with a system that is so exotic that no one would bother to develop an exploit for it - unfortunately, I haven't found one so far...

Privacy with Play Services

Hello all! I'm sure most of you are familiar with Google Play Services, the base of Google's Android framework and the brains behind all the Google things you do on your phone. Less of you, however, might also know that Play Services is notorious for being a beast of an application that no one truly knows the function of.
Below here is a rough explanation of Play Services from what I know about it. You can skip this if you already know and move on to the bread and butter of this post.
Play Services is proprietary software, meaning that its source code is not available to the public. All of Google's apps are proprietary like this as well. While developers like Chainfire have legitimate reasons to close off their app source code so others don't steal it, and so does Google, it is extra worrying from a company that makes a profit off of collecting userdata. Many people, including me, do not trust Google with our data, so we try to avoid their products as much as possible.
I thought that it would be nice to create a megathread of sorts with various users' suggestions on how to subvert the constant surveillance of Play Services, while also attempting to maintain the useful functionality of it. Below are some of the primary methods that I have thought of, and that I and some others have tried:
LineageOS/CyanogenMod Privacy Guard - If you are using LineageOS or any derivative thereof, you can go to Privacy Guard and deny certain permissions from Play Services. I and another user have denied permissions from Play Services without side effects, but your mileage may vary. @javelinanddart said on Reddit that Privacy Guard does indeed block permissions from Play Services and other system apps, so rest assured that Privacy Guard actually does something rather than being a placebo.
XPrivacyLua - This is an Xposed module that feeds false data to apps rather than blocking it entirely. I haven't tried this method myself, but the XDA post I linked above reports that XPrivacyLua works, even in tandem with Privacy Guard.
microG - microG is an open-source alternative to Play Services. It emulates many key functions of Play Services - push notifications, location services, etc - without the data collection running alongside such functionality. To clarify, this is a full replacement for Play Services, so you would flash a microG package instead of a GApps package. There are lots of bugs, though, even admitted by the developer. If you want to learn more, I suggest you visit the XDA thread for it, or view the implementation progress for various pieces of functionality.
There is nothing else that I know of, so if anybody knows of another viable method or can provide their own experiences with the above ones, your contributions would be appreciated by me and the rest of the privacy community.
Thanks for thread.
My only reason to use custom ROM is because they are GApps-free. In nearly every other aspect stock ROMs are better. Phones without good custom ROM I simply setup without Google account and install f-droid and yalp stores.
Another idea:
Imagine: Google is not as evil as we think: there are many privacy related settings in your Google account. You can login with a web browser and try through all these settings - and hope.
Device is a Samsung i9305 with RR-N-v5.8.5-final, Magisk v16.0, XPosed, XPrivacyLua, microG (via NanoDroid). No genuine Google services; Google Play Store is the one and only Google application installed.
I hope it suits into this thread (thanks very much for creating it!), and I'd like to share my settings. Please refer to the screenshots; I think it's self-explaining where they where taken from.
Actually no restrictions to microG, only to Play Store.
Remarks: µG has no restrictions in the firewall (AFWall+ Donation Beta); Play Store only granted internet access via WiFi and VPN. Just for completeness; running a RaspberryPi in the home network with Pi-Hole installed and acting as the DNS-server in the network. Unless using the home network i.e. using a foreign WiFi network or mobile data, ALWAYS establishing my own secure VPN to my RaspberryPi (with PiVPN installed) via OpenVPN and again the Pi acting as the DNS-server. If interested in further details please refer to this thread.
Thanks for this.
I was considering asking for a forum section here devoted to privacy, but it doesn't seem like a popular subject here. (After all, most of the people who have already picked the most snoopery OS in the world could be assumed to be not particularly worried about privacy. ? )
I come from a different motivation: the hope that by using a somewhat hackable OS, one can theoretically modify it in ways to achieve one's objectives, including privacy. But the last few years have made it rather clear that the Big G is working determinedly to foil such efforts.
Lately that seems to take the form of pushing more and more essential services into the Gplay frameworks, and deprecating perfectly working things like GCM in favor of intertwining it with Firebase, which may saddle us with that analytics data vacuum in order to get another essential service, push notifications.
Re: revoking permissions from Gplay frameworks, I feel like Google's determination to get their hands on data by hook or by crook (eg their ignoring of user preferences to disable various radios and enabling them in the background anyway, to track location and such) means they will quite possibly circumvent these preferences at some point as well.
As I mentioned in another thread I've experienced various problems in the past when I tried to aggressively restrict perms on the Gplay services using CM/LOS Privacy Guard, but perhaps some of that came from choosing interactive restriction prompts rather than blanket revoking. I do know that so many essential services are tied-into the Gplay frameworks these days that blocking tons of perms will inevitably cause breakage of some things depending how you use your device.
Jrhotrod said:
...
There is nothing else that I know of, so if anybody knows of another viable method or can provide their own experiences with the above ones, your contributions would be appreciated by me and the rest of the privacy community.
Click to expand...
Click to collapse
Due to your request above, please allow me to draw your attention to two threads by me. In these threads I tried about one and a half year ago to initially capture but also to update how I believe to have enhanced the battery duration, privacy and security of my GT-i9305 and how I went for a GApps-free device with microG.
Over the time until today, some of the described implementations, applications and measures became absolete or were replaced by others (e.g. using NanoDroid - or Nanomod as it was called in the beginning, since it has come out). Some changes occured due to the step from Marshmellow to Nougat or the non-availabilty of the official Xposed framework for Nougat in the very beginning. However, over all the time I've tried to maintain both threads updated and amended but currently not to much occuring on that frontline, probably because I've received a privacy status on our devices that obviously satisfies me in my personal opinion.
Oswald Boelcke said:
Due to your request above, please allow me to draw your attention to two threads by me. In these threads I tried about one and a half year ago to initially capture but also to update how I believe to have enhanced the battery duration, privacy and security of my GT-i9305 and how I went for a GApps-free device with microG.
Over the time until today, some of the described implementations, applications and measures became absolete or were replaced by others (e.g. using NanoDroid - or Nanomod as it was called in the beginning, since it has come out). Some changes occured due to the step from Marshmellow to Nougat or the non-availabilty of the official Xposed framework for Nougat in the very beginning. However, over all the time I've tried to maintain both threads updated and amended but currently not to much occuring on that frontline, probably because I've received a privacy status on our devices that obviously satisfies me in my personal opinion.
Click to expand...
Click to collapse
Wow, this is really great! Very high-quality thread.
Will add to OP later today
I apologise for the double post (original in my thread here) but I guess it also suits in this thread.
Found the below quoted post by @jawz101 in the XPrivacyLua thread here. Pretty interesting, and therefore I like to share:
Looking around on Data Transparency Lab website http://datatransparencylab.org/ - they fund grants for research in privacy stuff.
...I found an app called AntMonitor, an academic research project that does a MITM SSL cert + local VPN to look at sensitive traffic - even that which is encrypted. https://play.google.com/store/apps/d...it2.anteatermo
Anyways, it shows some apps trying to send my gps coordinates even though it doesn't have Android permission. Like, my coordinates are actually attempting to be sent encrypted to a destination. XPrivacyLUA doesn't trigger so I can only assume they grab my coordinates in a way that circumvents the traditional Android permission model.
To test, just try the app and open a few apps. I think it's apps with the Facebook graph API that is maybe doing it.
If you like ANTMonitor another app that does an SSL cert+ VPN is Lumen Privacy Monitor- a project by Berkely, but it doesn't seem to detect raw coordinates like ANTMonitor does.
Click to expand...
Click to collapse
However, I suggest to also follow the discussion/conversation between jawz101 and M66B, which has developed after this post.
Oswald Boelcke said:
Found the below quoted post by @jawz101 in the XPrivacyLua thread here. Pretty interesting, and therefore I like to share:
However, I suggest to also follow the discussion/conversation between jawz101 and M66B, which has developed after this post.
Click to expand...
Click to collapse
This is certainly an important discovery, thanks for the news.
Now for the sidenote that's 10x longer than the main comment. ?
One of the key issues I have with the various "privacy tools" is trying to figure out whether or not I trust all these entities that produce these diagnostic things to not be a solution worse than the problem when it comes to possessing and safeguarding my sensitive personal data.
It's getting to the point where I'm no longer enamored of giving *anyone* access to such stuff if I can help it, no matter *who* they are.
Even if they're not lying about their intentions and their commitment to security/privacy, there are still matters like carelessness/incompetence and targeted attacks to worry about.
@Exabyter: You're statement and expressed concerns are abolutely correct. Nothing to add except that I wouldn't limit it to "privacy tools" but especially include all applications that require root (and get it granted by the user) or all Magisk and Xposed modules. The latter should definitely concern.
My personal decision:
I'm not willing to trust anybody from the very beginning but I'm willing to trust single persons, groups or agencies. I've developed my own, private criteria, to which I stick but I've also admit the final decision isn't always based on rationality but also a lot on my feeling (in my stomage).
I don't held any confidential data on my device but privacy related ones, and I don't use my device for any kind of banking, shopping or payments.
I consider to use tools, modules and applications if their functionality rests within my defined specifications for the use of my device. Then I go for "the shopping tour" while I try to look into the details of the tools under closer examination, which includes where is it from, who's the developer etc.
I'll continue with the measures already described in one of my threads.
Oswald - I think we have largely similar stances on such things. In my case I will sometimes sway towards the pragmatic over the pedantic when the pedantic involves so many inconveniences that the tech becomes more of a burden than a help to me.
For example, I really don't like the idea of 3rd-parties keeping data pertaining to my daily geographic movements, but I also use several tools and services that by their nature rely on location data which could in some cases end up in the hands of parties I'd rather didn't have access to it. So I have to regularly weigh the apparent cost/benefit of such services and there are certainly some of them which have a high enough value to me that I willingly lower my default "protection level" in order to keep the other benefits of such tools/services.
Certainly microG is an important tool in that toolchest as it has a major disruptive impact on some of the most common ways Google and other parties snoop on users. But some of its imperfections also threaten to keep me from my ultimate goal of carrying a single phone which performs all the tasks I need to accomplish with it without undermining my privacy in a major way. (And ultimately, my freedom and agency as a citizen in a nominally and allegedly "free and democratic society", which is the actual "big picture" problem with privacy incursions in general IMHO)
I have spent several years now, with varying degrees of effort and success, trying to come up with a hardware/software solution to this problem, and I've never reached a point where I'm fully satisfied with the results. The fact that I am still carrying several mobile devices with me everyday is proof enough that I haven't achieved my objective in this regard and it gets tiring. As does all the time spent on venues such as XDA, researching, discussing and keeping-up with all the relevant issues, not to mention the large amount of time spent tinkering with HW/SW in order to keep all the special measures working. (And after we finally get things working more or less the way we want, we are faced with the particularly customized hardware wearing out, becoming unsupported, 3rd-party ROM and other compatible and necessary software being abandoned/deprecated, and so on and so forth.)
Truth to tell I'm a bit bitter about the amount of time/energy I have to spend to achieve something which should have been part of the mobile platforms in the first place. The current de-facto mobile platform duopoly certainly doesn't help matters.
---------- Post added at 03:39 PM ---------- Previous post was at 02:57 PM ----------
Now that I've gotten that philosophical rant out of the way ? ...
So as far as technical specifics:
microG of course is a big help as it either neuters or removes many troublesome anti-privacy vectors. For example, at the present time it does not support Firebase Analytics at all, which means (as far as I can tell) any app that expects to get telemetry on users via Firebase Analytics will not get anything if the app user's device is Gapps-free and using microG instead. (It remains to be seen if adding Firebase Cloud Messaging capability to microG will negate this presumed benefit. Cynics like myself are inclined to think one of Google's key objectives in deprecating Google Cloud Messaging and rolling push notification frameworks into Firebase instead was specifically to undermine the ability of users to avoid/circumvent Firebase Analytics)
XprivacyLUA looks interesting and is on my list to test. I found its predecessor Xprivacy to be an extremely tedious and labor-intensive option so I never seriously pursued it after my initial testing.
There are various tools I find handy to help get a sense of how dangerous certain apps may be to privacy. Here are a few:
AppBrain Ad Detector
https://play.google.com/store/apps/details?id=com.appspot.swisscodemonkeys.detector
Addons Detector
https://play.google.com/store/apps/details?id=com.denper.addonsdetector
Checkey (also on f-droid)
https://play.google.com/store/apps/details?id=info.guardianproject.checkey
Applications Info (also on f-droid)
https://play.google.com/store/apps/details?id=com.majeur.applicationsinfo
Permission Friendly Apps
https://play.google.com/store/apps/details?id=org.androidsoft.app.permission

Is a hard reset on an iphone secure to delete a sophisticated government spyware

by sophisticated government attack i mean something with virtualization technologies, several masking and hiding capabilities like FinFishers solutions.
Does:
Updating to the newest version of ios
hard reset the phone
securely remove the spyware?
1) i see more as a bonus question that is not really needed, but might be interesting too.
I would thank you for a careful but practical answer, since this question relates to some "moving parts" like: "Is it possible to load a "real" update from an infected phone, or will a sophisticated attack redirect those requests" and if there is something you can do to prevent this etc. or the question whether a hard reset really deletes everything or if the spyware can somewhat hide in "blocked" or wrongly addressed areas of the storage and so on.
On the other hand i do know that there never is absolute certainty and would be more interested in a "probabilistic view".
Thanks to the Forum!
I think your question is pointing to widespread security problems with most technology. Manufacturers often use closed source software and the same goes for most of the hardware devices. This makes security very difficult and of course these weaknesses are now being exploited by state sponsors.
Stuxnet was a good example and well worth reading about.
https://en.m.wikipedia.org/wiki/Stuxnet
http://itmanager.blogs.com/notes/20...e-protected-the-iranians-against-stuxnet.html
It infects microcontroller chips that do memory management. The introduced code returns modified data, maybe not even on each read.
So if the phone internal memory uses these microcontroller chips then even loading a new rom wouldn't help. You have to be able to have access to the microcontroller firmware and introduce your own access certification. It is very difficult to do this at present as most of the hardware information is not available, both for phone and internal chips.
Unfortunately this means that state sponsors can take the devices apart, inspect chips with an electron microscope, thus obtain a lot of secret information for their hacks.
Having had stuxnet on a laptop I became interested in these problems.
Contaminated updates again depend on the resources available. These rely on https and code signing.
https://arstechnica.com/information...ate-authorities-conspire-to-spy-on-ssl-users/
http://www.crypto-it.net/eng/theory/software-signing.html
A contaminated update requires access to the certificates and a delivery method such as intercepting a request from a known ip address.
Many states have access to the certificates and the means to target downloads. Using tor for updating might give some protection, as would a system to compare your download with that obtained by other people. We don't have this working automatically yet as far as I know.
https://www.torproject.org/docs/verifying-signatures.html.en
Phones have a second operating system where code may not be secure.
http://www.osnews.com/story/27416/The_second_operating_system_hiding_in_every_mobile_phone
https://www.rsaconference.com/event...ile-apt-how-rogue-base-stations-can-root-your
You can minimize risk by keeping a device in airplane mode and using a separate mifi device.
If you consider yourself an innocent target or just want to minimise risk then perhaps regularly buy second hand or new devices from shops, keep them in airplane mode, keep the necessary software to send by bluetooth and check the md5 sums.
Web browsers could be another security problem if they can run exploits, but this is probably outside the scope of your question.
Secure communications apps will probably work fine as long as they don't require updates. Beyond that, keep it all locked up in a safe you built yourself.

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