A security bug has been found in Facebook-owned instant messenger WhatsApp that could let attackers obtain access to a device and steal data by sending a malicious GIF file. The danger stems from a double-free bug in WhatsApp, according to a researcher going by the nickname Awakened, TheNextWeb reported on Wednesday.

A double-free vulnerability is a memory corruption anomaly that could crash an application or open up an exploit vector that attackers can abuse to gain access to users’ device. According to Awakened’s post on GitHub, the flaw resided in WhatsApp’s Gallery view implementation that is used to generate previews for photographs, videos and GIFs. All it takes to perform the attack is to craft a malicious GIF, and wait for the user to open the WhatsApp gallery, the report added.

“The exploit works well until WhatsApp version 2.19.230. The vulnerability is officially patched in WhatsApp version 2.19.244,” wrote the researcher. The bug also works for Android 8.1 and Android 9.0 OS but does not work for Android 8.0 and below.

In the older Android versions, double-free could still be triggered. However, because of the malloc calls by the system after the double-free, the app just crashes before reaching to the point that we could control the PC register, according to a report in Gizmodo.

Meanwhile, WhatsApp developers seem to be working on a new feature for the platform. As part of a new report, it looks like the company is working on introducing “disappearing” messages. This likely means that the company will introduce a textual function that is similar to the “WhatsApp Status”. For context, each WhatsApp Status in the Status tab disappears 24 hours after it is initially posted. It is worth noting that the developers are currently working on developing the feature.