how secure is an iPhone 4S+ with iOS 6+ in 2013?

Question

I was searching for the current status of iPhone security: there are many discussions on the subject but a lot of them are mostly hand-waving or related to old bugs/iOS weaknesses.

How secure an iPhone (4S+, iOS6+, 4 digits PIN, wipe after 10 unsuccessful attempts) is against dedicated attacks on data at rest (typical scenario: someone steals the phone and wants to access data within (emails, contacts, ...)). The phone is assumed to be patched with the current iOS -- I am looking for flaws more than bugs (which are likely to be fixed).

I want to put aside James Bond like scenarios and government-enabled spying (PRISM and similar), rather concentrating on enterprise espionnage (= reasonable money available to break a stolen iPhone). The closest I have come to so far is via the DFU (but I do not know if this is still current).

Answer 1

AFAIK there is no DFU mode bug publicly available for anything later than the iPhone 4 or iPad 1.

In terms of typical lost device scenario, assuming that the attacker can't guess the passcode before the device wipes (so set a relatively strong passcode an enforce device wipe on 10-20 incorrect attempts), I'd say that the device should be relatively secure.

There are lockscreen bypass bugs in current versions which could disclose some information from the device and also allow attackers to do things like make calls from it, and in iOS 6.x there was the malicious charger issue, but in general there are no deep flaws that I'm aware of which would compromise the security of the device if it's correctly configured and the attacker can't get access to it when it's unlocked.