UPDATED. iPhone 6s and 6s Plus phones running the latest version of iOS are plagued by a vulnerability that can be exploited to bypass the lockscreen and gain access to photos and contacts.
Germany-based security firm Vulnerability Lab reported the issue to Apple in mid-March, but after seeing that the company had not addressed the problem in iOS 9.3.1, which was released last week, it decided to publish an advisory detailing the bug.
Experts discovered that a local attacker can gain access to information stored on a locked iPhone 6s by using Siri to conduct an online search for email addresses via Twitter or other installed applications. The attacker can then bring up a context menu by pressing deeper on one of the email addresses displayed in the search results.
The menu that appears on the screen can be used to create or update contacts, which gives access to the list of contacts stored on the phone. Accessing one of the contacts in the list also allows the attacker to add a photo for that contact, which gives them access to the user’s photos.
Vulnerability Lab noted that if the hacker searches for an email address that already exists in the targeted phone’s contact list, they can also access options that allow them to send SMS messages and emails.
It’s worth noting that the lockscreen bypass only works on iPhone 6s and 6s Plus phones since these are the only models that include the recently introduced 3D Touch feature, which allows users to access various functions by pressing softer or harder on the display.
Until Apple releases a fix, users can protect their phones either by disabling Siri altogether, or by restricting the personal assistant’s access to user data.
This is not the only lockscreen bypass flaw found in iOS 9. Last month, Vulnerability Lab published a video showing several methods that could be used to gain access to data stored on a locked phone by “tricking” Siri. Vulnerability Lab told SecurityWeek that these issues have been addressed by Apple via a server-side fix instead of an iOS update.
Update: Apple told SecurityWeek that it patched the lockscreen bypass via a server-side fix rolled out early yesterday morning. Since it's a server-side fix, users don't have to take any action to protect their devices.