In early December 2015 and January 2016 Google made available further security updates for their Android smartphone operating system.
The December update addresses 16 security issues (all of which have been assigned CVE numbers (defined)(4x critical severity, 10x high severity and 2x moderate severity). That update brings Androids build number to version LMY48Z Android version 6.0 (known as Marshmallow) with Security Patch Level of December 1, 2015 or later address these issues. This update includes 2 fixes for security issues within libstagefright (both high severity) and 1 issue within both the Mediaserver (critical severity) and Media Framework (high severity) components.
Meanwhile the January update resolves 12 security issues (all assigned CVE numbers). That update when installed will show build version LMY49F As before, Android version 6.0 (known as Marshmallow) with Security Patch Level of January 1, 2016 or later address these issues. This update includes a fix for a critical issue in the Mediaserver component.
Why Should These Issues Be Considered Important?
As part of the December update a critical issue within Mediaserver was resolved that could be exploited by a remote attacker to allow them to carry out any instructions/actions of their choice (remote code execution). 3rd party applications could then be used to carry out the attacker’s actions with high privileges that they wouldn’t otherwise have. The issue can be exploited by sending specifically crafted media files within MMS messages (defined) or displaying those files on a specifically crafted webpage. Similar critical issues (3 in total) in the Skia graphics engine and Display driver can also use the above 2 means of attack mentioned above in addition to email. The final critical issue would have allowed malicious apps to carry out actions with root privilege (defined) allowing them full control over the smartphone.
For the January update if the MediaServer issue was exploited it could allow an attacker to use any emails, websites or MMS messages containing specifically crafted media files to remotely execute code (i.e. instructions or actions of their choice) due to a memory corruption issue corrected in this update. In addition, the critical issues corrected in the Display Driver (which interacts with high privilege with kernel) and the Android kernel (defined) are serious since the kernel can control any piece of the phones hardware and since it’s the core of the Android operating system it can be used to carry out any action/step since it has the highest level of privilege within the operating system.
How Can I Protect Myself From These Issues?
Updates to resolve these issues were made available by Google on 7th of December 2015 and 4th of January 2016. Manufacturers such as Samsung/LG etc. received these updates on the 2nd of November and the 7th of December respectively.
As mentioned by Sophos you may need to ask your device manufacturer or mobile carrier when this update will be made available to you. As discussed in a previous post regarding Android updates, please ensure to only apply updates from your mobile carrier or device manufacturer.
I followed this advice with my very recently purchased Sony smartphone which currently runs Android 5.0 (Lollipop). The Sony website shows that the latest build of Android they offer is already installed on my phone. The build is dated October 2015 (not shown in the image below). They do however show a logo below the build number that appears to suggest that at some time in the future the phone will receive Android 6.0 (Marshmallow). I have attached the image below:
The “Android” name, the Android logo, and other trademarks are property of Google Inc.
Copyright © 2011-2016 Sony Mobile Communications Inc. All rights reserved
I also contacted my network carrier and they stated that the device can run these updated versions of Android and that there is no reason why it wouldn’t have received such updates (assuming auto-updates hasn’t been turned off). As I said it appears that I received such updates up to October 2015 (I purchased the phone in November). They stated that Marshmallow will be rolled out in the future but no other details were provided. Neither of these answers are perfect and clearly demonstrate that while updates are being made available by Google and are being provided to the mobile carriers the update process (being used by the mobile carriers) needs to be streamlined for much faster deployment. I hope that you have better luck than I did.