This setting is available in android machine in following place Menu → Settings → Applications → Development
This options should be kept enabled only when you are a constant developer or you keep your handset connected to pc all the time. However this must be turned off before connecting to any non trusted machine.
Adb Shell root mode
This is one of the most dangerous setting of all. This setting allows adb shell to connect in root user mode. Effectively giving a root shell to whosoever gets usb connection to phone. Another tricky point about this setting is its activated only at boot time and during whole period of working the variable can’t be changed.
Also we need to keep this in mind that when this feature is enabled that means you don’t even need su binary to gain root access. You just need usb debugging to be enabled. Build.prop inside the ramdisk generally contains this value.
In order to check or modify the ramdisk you need to use following procedure. Location of build.prop : boot.img → ramdisk.cpio.gz → gunzip → un cpio → build.prop
Variable name : ro.secure Value : 0 = root , 1 = shell user If we look at this along with what was discussed in adb shell mode. We have a ready made root user shell which will give me full access to all files, flexibility to push and pull both from just about any level. In not so good hands this simple setting can cause a phone to lose all its important work.
Adb shell over wifi
Another variable which could be set to allow adb shell access. However this time access is over wifi network. Variable : service.adb.tcp.port = <tcp_port_no> To set this variable you can either place it in build.prop or use commandline #setprop service.adb.tcp.port=3355 This will mark port 3355 on phone to be usable to attach using adb. However in this case you need to restart adb service once. Combining this with above two settings and you have handed over your cell phone to one and all, while shouting in top of your voice : - PLEASE OWN ME. Note : this is a hypothetical attack as this is not yet a common habbit.
System permissions
In Android Devices, system partition is the most important partition which holds all the system critical files, as per general policy this partition is marked as RO i.e. readonly. However a general aftr market practice which is observed is to mark system partition as rw. The general use case is that by putting system in rw mode it is easy to work on modification of system data. The most harmful setting is if your ROM maker marks system with 777 i.e. rwx or read write execute permission for all users. When a system is marked with write permission it will allow a user to update / modify content of /system partition. Some of the crucial folders include /system/app or /system/bin. This permission is an open invitation to rootkits, malware, viruses and all simmilar items to start manhandling the device. Example in below scenario if some app gains root access they can modify any file in /system. However another variation is 777 for /system which effectively allows the whole world to modify the
This options should be kept enabled only when you are a constant developer or you keep your handset connected to pc all the time. However this must be turned off before connecting to any non trusted machine.
Adb Shell root mode
This is one of the most dangerous setting of all. This setting allows adb shell to connect in root user mode. Effectively giving a root shell to whosoever gets usb connection to phone. Another tricky point about this setting is its activated only at boot time and during whole period of working the variable can’t be changed.
Also we need to keep this in mind that when this feature is enabled that means you don’t even need su binary to gain root access. You just need usb debugging to be enabled. Build.prop inside the ramdisk generally contains this value.
In order to check or modify the ramdisk you need to use following procedure. Location of build.prop : boot.img → ramdisk.cpio.gz → gunzip → un cpio → build.prop
Variable name : ro.secure Value : 0 = root , 1 = shell user If we look at this along with what was discussed in adb shell mode. We have a ready made root user shell which will give me full access to all files, flexibility to push and pull both from just about any level. In not so good hands this simple setting can cause a phone to lose all its important work.
Adb shell over wifi
Another variable which could be set to allow adb shell access. However this time access is over wifi network. Variable : service.adb.tcp.port = <tcp_port_no> To set this variable you can either place it in build.prop or use commandline #setprop service.adb.tcp.port=3355 This will mark port 3355 on phone to be usable to attach using adb. However in this case you need to restart adb service once. Combining this with above two settings and you have handed over your cell phone to one and all, while shouting in top of your voice : - PLEASE OWN ME. Note : this is a hypothetical attack as this is not yet a common habbit.
System permissions
In Android Devices, system partition is the most important partition which holds all the system critical files, as per general policy this partition is marked as RO i.e. readonly. However a general aftr market practice which is observed is to mark system partition as rw. The general use case is that by putting system in rw mode it is easy to work on modification of system data. The most harmful setting is if your ROM maker marks system with 777 i.e. rwx or read write execute permission for all users. When a system is marked with write permission it will allow a user to update / modify content of /system partition. Some of the crucial folders include /system/app or /system/bin. This permission is an open invitation to rootkits, malware, viruses and all simmilar items to start manhandling the device. Example in below scenario if some app gains root access they can modify any file in /system. However another variation is 777 for /system which effectively allows the whole world to modify the
