There Is No Camera Lock Screen Bypass in iOS 5.1
There have been reports (and here) of iOS 5.1 containing a camera bypass tied to the new camera shortcut on the lock screen. The people who have reported this are sadly confused about the security timeout enforced by iOS’s Require Passcode setting (Settings > General > Passcode Lock > Require Passcode). If your Require Passcode setting is set to anything other than Immediately, then your device (and the camera roll from the camera shortcut) will be accessible for the entire duration of time specified (ie. 1 minute or 5 minutes).
As always, the best setting for Require Passcode is Immediately. That way you know that when you lock your device, it is actually locked, and will prevent someone from gaining access to it without the passcode within the minutes following the ‘lock’.
Sadly people seem all too eager to rush and report on iOS vulns before actually verifying them.
TDLR; There is no lock screen bypass in iOS 5.1 using the new camera shortcut. They were wrong.
Securing Siri on a Locked iPhone 4S
Although I haven’t had the chance to play with her myself (does that sound wrong?), Siri seems like an awesome addition to the iPhone. It’s worth pointing out, however, that it is still possible to use Siri when the iPhone is locked – presumably for convenient ease-of-use. Unfortunately this means that anyone with physical access to your phone can access information including contacts, calendar items, SMS/iMessages, and also make calls and send emails or messages from you.
[Update] There have been a whole bunch of people crying about how this is a major security flaw. Just to dispel some of the myth… this is not a security flaw, it’s a design decision that Apple made based on usability. Yes, it’s a default setting that may introduce some vulnerabilities, but then again there are still lots of people who run around without passcodes. To be honest I’m usually the first to secure the hell out of everything, but in this case I feel they made the right decision for two reasons. First, Siri is obviously less useful as a hands-free assistant if you need to unlock your phone every time; and secondly making it easier to use will help drive the adoption of Siri.
Luckily Apple thought of this on at least two levels. First, if you ask Siri to unlock your iPhone she’ll respectfully tell you that she “can’t unlock your phone for you”. Secondly – and this is the important one – it is possible to disable the use of Siri when the iPhone is locked. The option now lives in Settings > General > Passcode Lock, where you can set Siri to Off.
Needless to say (contrary to the screenshot), I recommend setting ‘Require Passcode’ to Immediately, turn Simple Passcode off so you can set a 5-or-more-digit PIN, set ‘Siri’ to off to prevent access when your iPhone is locked, and turn on Erase Data after 10 failed passcode attempts.
Siri is great, but let’s not make it easy for someone to social-engineer her into betraying you. See my other post for more details on protecting your iPhone from loss and theft.
In other news… you can tell Siri to use a specific nickname when talking to you. It’s important to note, however, that the nickname will be put into your VCard. So be careful if you tell her to call you her pimp, and then send someone your contact details ;)
Researchers Extract iPhone Data and Passwords in Minutes
A group of German security researchers from the Fraunhofer Institute for Secure Information Technology have discovered a way of extracting personal information and stored credentials from a locked iPhone, by way of a jailbreak. By gaining physical access to an iPhone (or iPad/iTouch), an attacker is able to reboot it into recovery mode, thus allowing them to upload their own jailbroken firmware onto the device. As part of this process SSH is enabled and a script can then be uploaded to the device which uses built-in system calls to extract encrypted data (including credentials in the keychain) from the device. See the video below for a demo of their attack, which can take as little as six minutes.
This attack would not be possible without existing jailbreak mechanisms, which effectively bypass the iPhone’s sandbox and allow unsigned code to be executed. The second issue is the way that iOS handles stored data and credentials, allowing any application to request the information. This is actually a prime example of the dangers of having a jailbroken iPhone or iPad, as it makes it much easier for an attacker to execute malicious code on your device.
These kinds of issues are not isolated to iOS devices, and the same would exist on other devices that could be made to run custom scripts. This will be a tricky issue for Apple to resolve, as much of its security relies on a strong sandbox. Their best chance is to try to identify and patch as many of the vulnerabilities that could be used for a jailbreak. They will also need to review the way iOS handles encrypted data, and ensure that data cannot be extracted by arbitrary applications.
Luckily there is not yet a publicly available automated tool to perform this attack, so it is unlikely that a random thief will be obtaining your data. If you’re really worried, you can use Apple’s free Find My iPhone service to remotely wipe your iOS device should it be lost or stolen. Check out my article on protecting and recovering your iPhone from loss and theft for more information.
The team’s original research paper is available here (PDF).
iOS 4.2 Update Fixes Passcode Bypass Bug
The upcoming iOS 4.2 update, recently seeded to developers, fixes the recently-discovered keylock/passcode bypass bug. The bug allows any user with access to a locked iPhone to make phone calls, view/modify contacts, and send/view emails, by exploiting a simple bug on the “Emergency Call” screen.
Full details of security patches in this update will be announced upon release.
[Update] iOS 4.2.1 has been released.
Making Calls Using Keylock Bypass Bug on iOS 4.1
A keylock bypass bug has been found in iOS 4.1 which allows unauthorised users circumvent the passcode screen to make calls. It’s a pretty simply trick which involves entering a number (eg. 1) on the ‘Emergency Call’ screen, pressing Call and then immediately pressing the lock button. This brings up the Phone app where the user can pick a name from the contact list, or enter a phone number of their choice. To return the phone to normal (without rebooting it), just hold down the Home button until the Voice screen comes up, press Cancel, and then the lock button.
You are able to add/delete contacts, and open the Mail app by sharing a contact where you can then create and send emails.
Here’s a demo:
I’m running 3.1.3 on an iPhone 2G, and for some reason I can make arbitrary calls directly from the Emergency Call screen without any fancy tricks. Go figure.
These kinds of vulnerabilities are not unique to iPhones however, with similar bypass bugs being found in some Android-based phones.
[Update] Thanks Andy for clarifying what an attacker can do using this technique.
[Update 2] This bug has been fixed in the iOS 4.2 update.
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