WhatsApp & Telegram keep your messages encrypted before it gets delivered to the receiver. But this doesn't happen with the media files, these are not encrypted.
In a blog post, researchers from Symantec have explained how a vulnerability in WhatsApp and Telegram can lead to hijacking of media files when sent using the affected devices. This security flaw is termed as "Media Files Hijacking". This vulnerability is affecting the WhatsApp by default and Telegram when certain features are enabled. The platform being affected here is Android.
How does this vulnerability work?
The hackers mainly take advantage of the time-lapse between when the media files are received through WhatsApp and telegram are written to the disk and when they are loaded onto the app's chat UI. This time-lapse provides an opportunity for hackers to intervene and manipulate those media files without the user's knowledge and permission.
In Android devices, instant messaging apps like WhatsApp, Telegram etc lets you choose the location to save your incoming and outgoing media files in both the internal storage or the external one.
Whatsapp, by default, stores the media files in the external storage and this same happens on Telegram if "Save to Gallery" feature is turned on in this app. It is to be noted that files which are saved in internal storage are only accessible by the app itself and it means that these files can be accessed by other apps. But when media files are stored in external storage then these files can be modified by other apps. So, it is advised to use internal storage to store files and data to keep it safe from other apps.
How to get rid of this situation?
WhatsApp and Telegram users need to change the setting provided below to protect your media files from getting hijacked.
- WhatsApp users: Visit Settings and disable "Media Visibility".
- Telegram users: Turn off the "Save to Gallery" feature.