From my point of view and with my rather poor knowledge of iOS, the principle of a sandbox in iOS is the following:
- each app and its data is installed in a private area within the partition, but each app runs under the same user 'mobile'
- the sandbox only allows restricted and controlled access to system ressources (i.e. system files)
- the sandbox only allows restricted and controlled access to ressources like contacts, sms, mail, internet...
- the sandbox prevents an application from attacking another application's data
Are there any important functions of the sandbox that I left out?
I assume that with a jailbroken device, all security functions of the sandbox are obsolete (i.e. an attacker can easily read data from other applications, can access system files etc)?