Defect that Android smart lock can be avoided using Viber application is found

A service that allows you to send and receive text messages to and from the smartphone on which you installed the application free of chargeViberAccording to Google Play, there is no need to create an account or log in like Skype, and 50 to 100 million times are downloaded for Android only, but with this Viber application you can download Android smartphone A fatal flaw in the lock function can be found in the Viber application.

Critical flaw in Viber allow full access to Android Smartphones, bypassing lock screen - Top News - Bkav Corporation
http://www.bkav.com/top-news/-/view_content/content/46264/critical-flaw-in-Viber-allows-full-access-to-android-smartphones-bypassing-lock-screen


Critical app flaw bypasses screen lock on up to 100 million Android phones | Ars Technica
http://arstechnica.com/security/2013/04/crital-app-flaw-bypasses-screen-lock-on-up-to-100-million-android-phones/


The situation that actually using Viber to avoid the lock of Samsung Galaxy S II is as follows.

Exploiting Viber to bypass lock screen of Samsung Galaxy S II - YouTube


First of all, I lock the smartphone.


Next, another smartphone is prepared. Start up Viber and tap "Send Message".


Locked smartphone will let you know that you received a message with "1" in popup. Tap the button to display the Viber keyboard.


Although the keyboard was displayed for a moment, it will be gone soon as it is locked. On the right smartphone, I send the message "2" again.


The smartphone that is locking again receives a message, this time press the Back button without displaying the keyboard.


Then the home screen was displayed.


It should have locked, but now I can operate the smartphone freely.


In the same way, you can avoid locks on smartphones other than Samsung Galaxy S II as well. Next is Google Nexus 4.

Exploiting Viber to bypass lock screen of Google Nexus 4 - YouTube


Followed by Sony Xperia Z.

Exploiting Viber to bypass lock screen of Sony Xperia Z - YouTube


HTC Sensation XE has a slightly different way to avoid locking, combining messages and one call. .

Exploiting Viber to bypass lock screen of HTC Sensation XE - YouTube


First of all, we lock on one smartphone.


I will call from another smartphone using Viber.


When I immediately hung up, I was told that there was an incoming call on the locked smartphone.


I will send you a message.


Received a message with locked smartphone written "1".


Like the Samsung Galaxy S II, do the operation to display the Viber keyboard.


I will send you a message.


Press the Back button ......


It has become possible to operate the smartphone which should have locked it freely also here.


Like this, although there are some differences in the method depending on the model, it seems that locking can be avoided with many Android smartphones such as Samsung, Sony, HTC and so on. This vulnerability will be released on the 23rd of this week, Viber will recognize this fact on the 24th and will release releases of the application modified next week. The popup function displayed when a message arrives can be turned off from the setting screen, so Viber is calling Android users not to use the popup function for the time being.