The devices running Android 4.3 or higher versions, have reported a new bug in the OS triggered by a malicious file which can turn off the audio on your device.
This bug is instigated by a malformed MKV file or a malicious application on your device which will then elicit buffer overflow in the mediaserver service. This buffer overflow will then result in a full stop to all the audio on your android device. Apart from that, in certain scenarios it has been found to make your android device unresponsive by utilizing the RAM available for performing various tasks.
The bug has been identified by the Trend-Micro couple of months back wherein when it was submitted to Google and it’s vulnerability has been marked as low priority. The low priority is given in accordance with the guidelines and consequences as rated by the Google. Not to miss that, any vulnerability which can be fixed by a just reboot is categorized as low priority. For more information on google’s priority rating and consequences one can read here.
DO NOT download files from the messages appearing to be from the people you do not know or trust or the message is not an expected message from the trusted source. This will help you to avoid getting in the scenario mentioned here. However, by chance you get fall prey to this, then don’t panic and simply reboot your android device and delete the recently downloaded files which will be the expected source of the malicious content.