Earlier today, talented developer alephzain described a security vulnerability affecting most if not all Exynos 4 devices, which represent dozen of millions gadget out there.
Unfortunately he also released a working exploit with complete source code before the various vendors affected (Samsung, Meizu and surely others) were made aware of it, leading to a severe security issue without accessible fix for now.
I wrote then an application to circumvent the issue while manufacturer patch the security hole and publish OTA updates.
However, please note its a partial fix that cannot secure completely your device which is to date impossible without modifying it − an operation that will stop the ability to install OTAs without an external tool.
That’s why I would still recommend to consider Chainfire’s solution linked below.
Characteristics of this app:
- Works on any device, let you know if your system is vulnerable
- Doesn’t require root to apply the fix
- Doesn’t modify your system, copy files or flash anything
- Fix can be enabled or disable at will
- Free of charge
- Break proper function of the Front camera on some Galaxy S III and Galaxy Note II Samsung official firmwares when activated.
Workaround: enable HDR or Low light photography camera mode. Both blend multiple exposures.
- Might alter MHL/HDMI output functions on some devices (not confirmed)
- Cannot protect efficiently against some potential attacks (typically, on boot).
The real fix by manufacturers or some carefully written custom kernels will indeed be the only true solutions to this vulnerability − and won’t introduce any feature regression like this one does with some firmwares on cameras.
- Comes without any kind of support or warranty.
- Circumvent a random behavior nature in the exploit and try harder in case of initial failure to apply the fix at boot.
- Notify the user in case the application was unable, for any reason, to apply the fix (you need to enable it manually then)
- Improve efficiency if the apply on boot feature by some modifications after study of earlier versions published by Chainfire.
- Minor: remove unused asset to reduce application size of 16kB.
- Add camera HDR or Low Light capture modes workaround tip in fix description.
- Add missing Internet permissions for Flurry analytics:
I will likely share installation figures with my Samsung security contacts, so they get an idea of the interest generated by this kind of early fix.
- Clarify apply on boot limitations.
- Increase the chances to run early at boot.
- Improve descriptions.
- Fix link to this page inside the app.
First version, 0.1
- There’s an XDA-forums thread for feedback.
- Chainfire made an app easily rooting your device instead (this app has no relation with rooting whatsoever)
Credits to him too as it was fun sharing mind when reading the exploit earlier today.
- Redistribution of this APK outside of this web page is forbidden, please link this web page directly that I’ll keep updated.
- This application is not released on Google Play because it use the vulnerability itself as test and tool to protect against itself (yes ^^)