This post details the step-by-step method required to extract a plist/OAuth token from a standard (non encrypted) iTunes backup of any iOS device (iPod Touch, iPhone and iPad) and then copy this onto another device to automatically log in using those creditials.
NOTE: The process outlined below will not work if you have iTunes set to encrypt your iOS backups. This method was confirmed as working as of 10th April 2012 using the latest iOS xxx and current Facebook (v.4110.0), Dropbox (v1.4.6) and LinkedIn (v35) iOS apps. You do not need to have a jailbroken iPhone or iPad for this to work. I do not condone using the methods below to gain access to anybody’s accounts without their prior permission, I hold no responsibility if using the information in this post lands you in trouble with your ex partner, current partner, your boss, the police, your kids, etc.
In case you weren’t aware a security flaw was found by Gareth Wright earlier this week that allows your Facebook login key to be copied form one iOS device to another and essentially allow a 3rd party access to your account without needing to know your account email address or password. The same vulnerability has also been found in Dropbox, LinkedIn, Tumblr, Vimeo and 1Password. At the time of writing this post, Dropbox have said they are going to address the problem and 1Password have gone one step further and rewritten the way the user details are stored so this exploit cannot be used anymore and have submitted the update to Apple for approval before it’s released. Facebook appear to dismiss the security vulnerability saying it is only really an issue if your device is jailbroken or you use a 3rd party app to access the files on your iOS device. WRONG! If you have ever connected your iOS device to iTunes via USB and iTunes has taken a backup of your device then you are at risk (unless you tick the box to encrypt your backups, in which case rest easy and don’t worry about anything written below). The plist file that is the centre of this whole security flaw is copied to your computer via iTunes backup, no third party app here extracting files as Facebook suggests. Granted you need a third party app to access the file and place it onto another iOS device but crucially, the insecure file is copied to your computer during a normal iTunes backup.
What does this mean to most end users then? Probably not a lot to be honest. If you only ever connect your iPhone or iPad to your own personal computer then there’s nothing to worry about since the insecure file, locked away in the backup of your device, resides on your personal machine and nobody else can get to it easily. But in today’s modern and social society, the likelihood is that you have a computer you share with your wife, girlfriend, housemates, family or you have been at a friends house with a low battery and connected your iPhone to give it a little extra juice. This is where things become a little more vulnerable, if the computer you connected your device to made a backup of your device (remember a backup is always made when you are updating the iOS via iTunes) then the crucial plist file with your OAuth key in for apps such as Facebook, Dropbox, LinkedIn and more now reside on that computer in that backup.
So if you currently share a computer with your partner and want to log into Facebook as them, you can if you follow the steps below. Likewise, if your ex-partner used to connect their iPhone or iPad to your computer but left you several months ago for somebody hotter, then you too can dip into their old backup on your computer and log into Facebook and other apps as them. [Again I re-iterate the moral/legal implications of such actions]
Step by Step Guide
Ok so how can you hack into somebody else’s Facebook using a file from their iOS backup? You’ll need two pieces of sofware:
1 – to read the backup files an extract the plist file
2 – to allow you to drag and drop plist files onto your current iOS device
Let us pretend you want to gain access to your ex-girlfriend’s Facebook account and you know that she used to connect her iPhone or iPad to your computer. The first thing to do is open up iTunes and go to Preferences and select the Devices icon along the top which lists all device names that are backed up on your machine along with date of the backup.