With version 2.19.20, WhatsApp has increased the security of the messenger. Many users have wanted the screen lock for a long time - but it seems to have a problem.
WhatsApp Update 2.19.20 – the screen lock for the messenger – was released at the beginning of February. For the first time, users could activate the biometric recognition method Touch ID or Face ID as needed, thus protecting content from prying eyes. Now it turns out that the feature contains a serious bug – the authorization can be easily bypassed. This affects all users who have activated their screen lock but have not set the time period to "immediately." To bypass the lock, iOS's own sharing menu is sufficient. Here, the unauthorized user can, for example, go to the "Photos" app and select an image from there, then click "Share to WhatsApp." All chats will now be listed. Once this step is completed, the process can be canceled and the app closed. If you now go to WhatsApp directly, you can access all chat histories without any biometric verification.
Better safe than sorry
Again, this process only works if the user hasn't set the screen lock to "instant." We've tested it ourselves, of course, and can confirm the error. Until WhatsApp releases an update to fix the issue, this is the only way to ensure protection from prying eyes—assuming third parties can access an iPhone unnoticed and know the unlock code. Here you can read how the screen lock in WhatsApp is activated.
*Update: The bug was fixed with version 2.19.22
