Back in the time of feature phones, it was pretty common to send out a nefarious piece of software wrapped as a text message. Apparently, the trick works on Nexus phones now which may reboot when hit with a barrage of Class 0 text messages.
Class 0 text messages are essentially such SMS which are not automatically stored on the handset. IT administrator Bogdan Alecu has now discovered that a number of Nexus devices such as Galaxy Nexus, Nexus 4 and Nexus 5 contain an Android bug which can be exploited using these SMS.
When a large volume of Class 0 SMS are sent to a Nexus handset, they act as a denial of service attack. In order to tackle this, the messages app crashes or the phone simply reboots on its own. Another possibility is that the handset disables the network connection and so, stops the stream of harmful text messages.
However, the possibility that such an attack may restart a Nexus handset is certainly worrying. Unexpected reboot can cause significant data losses and you may not be able to recover all of this data later. The good news is that Google is currently looking into the problem and aims to resolve it. We can expect a subsequent version of Android patching this vulnerability to arrive soon. Alternatively, Google may dish out a stand-alone patch to resolve this.
In the mean time, you can head straigh to this firewall app and install it. It will keep you safe from the SMS messages exploit if you are using a Nexus handset.