The issue called /dev/exynos-mem, if exploited, lets any application complete access to the RAM and the kernel.
Three libraries seems to use /dev/exynos-mem is /system/lib/hw/camera.smdk4x12.so, /system/lib/hw/gralloc.smdk4x12.so and /system/lib/libhdmi.so
To check if your device is affected, open a terminal emulator and type the ls -l /dev/exynos* command. If this returns, crw-rw-rw- in the output, your device is affected and you should take extreme caution before installing any suspicious apps from the Play Store.
Samsung is yet to comment on the issue but several developers have already submitted quick fixes. Initial patches fixed the issue but also rooted the device along the way. Now Françoid Simond, creator of the popular VooDoo Sound app for Android, has released his own fix, which takes care of the issue without rooting the device. You can download the patch for your device here.
