On Friday, Jay Freeman announced on Twitter that he exploited a known vulnerability and subsequently achieved root access to his developer-model of Google Glass – Google’s highly anticipated, wearable, head-mounted computer.
Around the same time, another notable hacker, Liam McLoughlin, tweeted that he exploited the same bug to achieve shell and later root access.
Freeman, a mobile researcher and self-proclaimed technology consultant, is also known by the handle ‘Saurik.’ He is perhaps best known as a jailbreak proponent, having developed Cydia, a popular application that enables the installation of other applications on rooted iOS devices. Jailbreaking is a process through which users exploit hardware or software vulnerabilities to unlock mobile and other computer devices, freeing them from the limitations of built-in, proprietary software.
On Twitter, Freeman wrote that Google Glass runs on Android 4.0.4; a version of the Jelly Bean mobile operating system that apparently contains a restore vulnerability in the Android debug bridge that, if exploited, leads to a race condition.
In an Interview with Forbes’s Andy Greenberg, Freeman explained that he achieved his jailbreak by backing the device up, then modifying the backup file before restoring it to the device. During the restore process, Freeman says he redirected certain restore-data in order to overwrite a critical configuration file. This process tricked Google Glass into thinking it was running a fully-controllable Android emulator that developers use to freely test mobile applications on traditional laptop or desktop environments.
McLoughlin, who is also known by the palindromic handle Hexxeh, tweeted similarly that, “There’s a “debug mode” option on Glass that appears to enable ADB access. I got a shell on my Glass.” He noted that he had not yet achieved root-level access. Shortly thereafter, McLoughlin tweeted that root access was easy as well, claiming that “reboot-bootloader gives you a fastboot original equipment manufacturer (OEM) unlock.”
It should be noted that Freeman and McLoughlin performed their jailbreaks on a pre-release, developer model of Google Glass. The consumer variety of Google Glass will likely differ from the dev-model and it’s hard to say whether these exploits will work on the publicly available model.
In response to the McLoughlin hack, Tim Bray of Google tweeted, “Yes, Glass is hackable. Duh.”
Another Google employee, Dan Morill, was quick to clarify on his Google Plus page that, technically speaking, Freeman’s hack did not achieve root access, but was rather a “fastboot OEM unlock.”