No Click Excitement: Interaction-Less Vulnerabilities in Messaging Apps
October 20, 2021
Google researcher Natalie Silvanovich has made it her mission to investigate one particular type of vulnerability—one that allows attackers to access video and/or audio without the victim so much as clicking a link. Wired discusses her unnerving findings in, “Messaging Apps Have an Eavesdropping Problem.” Writer Lily Hay Newman tells us:
“Silvanovich has spent years studying “interaction-less” vulnerabilities, hacks that don’t require their targets to click a malicious link, download an attachment, enter a password in the wrong place, or participate in any way. Those attacks have taken on increasing significance as targeted mobile surveillance explodes around the world.”
The resolute researcher presented her findings at the recent Black Hat security conference in Las Vegas. Her search turned up bugs in apps domestic and foreign, from Facebook Messenger, Google Duo, and Signal to JioChat and Viettel Mocha. The vulnerabilities she found were eagerly patched by the respective developers once she notified them, but her discoveries reveal a problem more widespread than had been suspected. It seems that some of the vulnerabilities resulted from honest mistakes by developers using the open source communication tool WebRTC. Other times, though, it had to do with how an app connects calls. We learn:
“When someone calls you on an internet-based communication app, the system can start setting up the connection between your devices right away, a process known as ‘establishment,’ so the call can start instantly when you hit accept. Another option is for the app to hang back a bit, wait to see if you accept the call, and then take a couple of seconds to establish the communication channel once it knows your preference. … Most mainstream services take the other route, though, setting up the communication channel and even starting to send data like audio and video streams in advance to offer a near-instantaneous connection should the call’s recipient pick up. Doing that prep work doesn’t inherently introduce vulnerabilities, and it can be done in a privacy-preserving way. But it does create more opportunities for mistakes.”
Concerned users may want to favor Telegram—Silvanovich found that app takes the slower but safer route. Though the snippets hackers can capture with these vulnerabilities may or may not be valuable, many find it worth a try—such attacks are difficult to detect and to trace. Careful design and implementation on the part of app developers are the keys to avoiding such breaches, she tells us.
Cynthia Murrell October 20, 2021