Pierluigi Paganini March 09, 2016

A large percentage of Android devices is affected by security vulnerabilities that could be exploited by attackers to easily gain a Root Access.

According to experts at TrendMicro a large percentage of Android devices in use today is affected by security vulnerabilities that could be exploited by attackers to easily gain a root access.

The attack allows an ill-intentioned to escalate the privileges of any code that is executed on a target device, however, this attack scenario sees an attacker having installed his malicious code onto the device in the first place.  Android users need to be very careful of installing any mobile apps from untrusted sources.

Below the description provided by TrendMicro for the CVE-2016-0819 and CVE-2016-0805 flaws discovered by its experts:

CVE-2016-0819

We discovered this particular vulnerability, which is described as a logic bug when an object within the kernel is freed. A node is deleted twice before it is freed. This causes an information leakage and a Use After Free issue in Android. (UAF issues are well-known for being at the heart of exploits, particularly in Internet Explorer.)

CVE-2016-0805

This particular vulnerability lies in the function get_krait_evtinfo. (Krait refers to the processor core used by several Snapdragon processors). The function returns an index for an array; however, the validation of the inputs of this function are not sufficient. As a result, when the array krait_functionsis accessed by the functions krait_clearpmu and krait_evt_setup, an out-of-bounds access results. This can be useful as part of a multiple exploit attack.

The problem affects the Qualcomm Snapdragon systems on a chip,  more than a billion devices is at risk. The root access to a mobile device allows an attacker to conduct a number of malicious activities, from surveillance to financial frauds.

The vulnerability could be exploited by simply running a malicious app on snapdragon-powered Android devices. Experts at TrendMicro privately reported the security holes to Google that fixed them.

As usually happen in these cases, the high fragmentation of the Android market complicates the patch management process. Many users are still vulnerable to the attack waiting for a security patch.

“As the number of embedded SoCs in devices explode with the IoT growth, we anticipate that these kinds of vulnerabilities will become a bigger problem that will challenge the overall security posture of Internet of Things.” continues the post published by TrendMicro.

Going into technical details, the flaws could be exploited in every mobile and IoT devices that could allow the invocation of the system call perf_event_open. Fortunately, many vendors can have customized the kernel and SELinux policies in order to avoid the call.

According to the Nexus Security Bulletin – February 2016, the CVE-2016-0805 vulnerability affects versions earlier than 4.4.4 to 6.0.1, this means that Nexus 5, Nexus 6, Nexus 6P, Samsung Galaxy Note Edge are vulnerable to the attack.

“We believe that any Snapdragon-powered Android device with a 3.10-version kernel is potentially at risk of this attack. As mentioned earlier, given that many of these devices are either no longer being patched or never received any patches in the first place, they would essentially be left in an insecure state without any patch forthcoming.” conclude TrendMicro.

Pierluigi Paganini

(Security Affairs – Android devices, Qualcomm Snapdragon)