The “view once” feature for media files in WhatsApp seems to be not so unique after all. Developers have discovered an easy way to save these files.

One of WhatsApp’s most popular features is the “view once” feature for images, videos and voice messages. For example, users can send an image that the recipient can open once for a few seconds, after which the photo disappears. At least that’s what we thought until now. Developers at the startup Zengo have discovered an easy way to retrieve these images due to a bug in the system. The privacy that WhatsApp promised us turns out to be not so secure after all.

Multiple display?

You’ve probably posted a silly photo in your WhatsApp group with friends using the “view once” feature, thinking they wouldn’t be able to save it or revisit it anyway. Well, next time you should think twice before sending such a photo. Developers at startup Zengo have discovered a bug in the system that causes images to continue to be found under the guise of “view once.”

“The ‘view once’ media messages are technically the same as regular media messages, except that the ‘view once’ flag is set,” said co-founder Tal Be’ery. “This means that it is effectively like putting a note on the photo saying ‘don’t look.’ To bypass this, attackers simply need to set this flag to false. The media can then be easily downloaded, forwarded, and shared.” In the video below, the engineer demonstrates how this works.

The Be’ery team informed WhatsApp about the issue on August 26. A spokesperson later confirmed that the issue was registered and under investigation.