WhatsApp reveals your personal data without you realizing it
WhatsApp displays a preview for every link sent in a chat by default. This preview consists of an image, a title, and a short text from the linked page. For users, this feature seems useful; it helps the message recipient assess the content of the link and its importance or sensitivity. However, what many do not know is that this function can reveal mehr Informationen – additional information about them.
According to the platform "WABetaInfo", WhatsApp, when sending links and with the preview feature enabled, sends the sender's IP address to the server of the linked site. In this way, third parties can obtain sensitive data about users, such as their approximate location on the map, their internet connection times, and their browsing and movement patterns on the network.
A similar problem also appeared in Apple's iMessage service. In 2016, developer Ross McIlwraith explained in a blog post that the iMessage service not only reveals the IP address but also shows information about the device being used. In this case, link requests are sent directly from the user's phone or tablet to the site.
Link previews are also available in other services like Slack and Facebook. However, these services use what is called a "Proxy", which is an intermediary server that stands between the user's device and the site being accessed. This intermediary prevents sites from seeing the user's real IP address, which helps protect privacy. When this protective shield is not present, it can be systematically exploited to gather detailed information about connected devices and their owners' behavior.
Currently, WhatsApp allows users to disable the link preview feature to better protect their data. To do this, you need to go to the app settings, then select the "Datenschutz" (privacy) section. There, several options appear, including the ability to disable the "Linkvorschau deaktivieren" (disable link preview) feature. Once this setting is activated, the app stops creating automatic previews for links, thus reducing the amount of data that may reach external sites.