Independent researcher Indrajeet Bhuyan was the one who discovered this particular bug, where to “trigger” the bug, all that one needs to do is to send a whopping 4,000 smileys to a target, which would then see the app “overflow the buffer” before resulting in a crash. This is not too different from a bug that Bhuyan also detected in 2014, where WhatsApp crashes after receiving a 2,000 word message that is written using a special character set.
Which versions of WhatsApp are vulnerable to the 4,000 smiley bug? The latest version of ‘WhatsApp for Android’ which runs on Android Marshmallow, Lollipop and Kitkat versions, as well as ‘WhatsApp for Web’ when it sees action in Chrome, Opera and Firefox. Anyone wants to test it out in WhatsApp clients for Windows Phone and iOS?