When a series of 30 flash SMS are sent to the Android 4.x-based Nexus device, it renders the phone unresponsive and causes it to, restart, freeze or even lose network.

The bug was discovered by Bogdan Alecu, a system administrator at Dutch IT services company Levi9 at a security conference in Romania. It was found to affect Google Galaxy Nexus, Nexus 4, and Nexus 5.

Alecu said that 20 different devices from various vendors had also been tested, however, they were not found to be vulnerable to this problem

According to PC World, the special message is a class 0 SMS or Flash SMS which gets displayed directly on the phone’s screen and doesn’t automatically get stored on the device and users may choose to save or dismiss it.

However, the Flash message on Google Nexus gets displayed on top of all active windows and is surrounded by a semi-transparent black overlay that has a dimming effect on the rest of the screen and with every message received the dimming effect increases.

Alecu found that when a large number of Flash messages, around 30, are received and are not dismissed, the Nexus devices will either reboot or disconnect to the network when PIN is asked. During the attack, users won’t be able to even receive calls or messages.

Alecu claimed that he contacted Google several times since he found the flaw, but mostly got automated responses, the report added.