An attack on group FaceTime calls in 2019 would have allowed attackers to activate the microphone and camera of the iPhone they were calling, and then eavesdrop on the recipient before they did anything. Apple used a nuclear option to block access to group-calling until a fix could be found. Natalie Silvanovich was captivated by the vulnerability and the fact it didn't require any taps or clicks on the part the victim.Silvanovich, a Google Project Zero bug-hunting researcher, said that if you find a bug, it could cause a call to be answered instantly. I went on a little tear and tried to find these weaknesses in other applications. I found quite a few.Silvanovich spent many years researching interaction-less vulnerabilities. These hacks don't require targets to click malicious links, download attachments, enter passwords in the wrong places, or take part in any other way. These attacks are becoming more important as targeted mobile surveillance booms all over the globe.On Thursday, Silvanovich will present her findings on remote eavesdropping bugs within ubiquitous communication apps such as Signal, Google Duo and Facebook Messenger as well as international platforms JioChat, Viettel Mocha, and popular international platforms JioChat. Silvanovich claims that all of the bugs were fixed and that developers responded quickly to her disclosures. The sheer number of flaws discovered in mainstream services is a reminder of how widespread they can be, and why developers should take them seriously.Silvanovich says that when I first heard about the group FaceTime bug, I assumed it was an isolated bug that would never happen again. It is something that we didn't know before but it is important for people who create communication apps to be aware of. Your users are making a promise that you won't suddenly transmit audio or video at will. It is your responsibility to ensure that your application keeps that promise.Silvanovich discovered a variety of vulnerabilities that could allow an attacker to spy on a target's phone. An attacker could have listened to audio from the target's device using the Facebook Messenger bug. Both the JioChat and Viettel Mocha bugs could have given advanced access to audio or video. Signal exposed only audio. The Google Duo vulnerability allowed video access for a short time, but not for long. An attacker could capture screenshots or record frames during this period.Silvanovich examined a variety of apps that built much of their audio- and video calling infrastructure using real-time communication tools provided by the open source WebRTC project. Developers who misunderstood WebRTC's features or poorly implemented them are some of the causes of interaction-less calls. Silvanovich claims that there were other flaws in the design of each service's call setup and when it does so.The system can establish a connection between your devices immediately after you accept a call from someone via an internet-based communication platform. You can also wait for the app to call you back, then wait for you to accept it. Then, the app will establish the communication channel after it has established your preferences.