‘Mute’ Button In Conferencing Apps May Not Actually Mute Your Mic

According to a new study, pressing the mute button on popular video conferencing apps (VCA) does not always perform as planned, with apps listening in on your microphone. Furthermore, in the software under examination, pressing mute does not prevent audio from being sent to the apps’ servers on a continuous or periodic basis. Also, users have a poor understanding of how the mute system works as a result of this activity not being described in linked privacy policies, mistakenly assuming that audio input is cut when they use it. 

Though, the misconception is reflected in the first phase of the study. Which rotates around surveying 223 VCA users on their prospects while pressing mute. Also, several (77.5%) respondents find it objectionable for the apps to continue to access the microphone. And possibly collect data when the mute mode is active. Therefore, the study was directed by a team of researchers at the University of Wisconsin-Madison. And the Loyola University in Chicago, who published a paper on their results.

When is the mute button in conferencing apps not actually muted?

Mute button in conferencing apps

Furthermore, as part of the study, the researchers carry out a complete runtime binary analysis of chosen apps. To decide what type of data each app collects and whether that data constitutes a privacy risk. Although, the apps tested in this phase of the study were Zoom, Slack, MS Teams/Skype, Jitsi Meet, Discord Google Meet, Cisco Webex, BlueJeans, WhereBy, and GoToMeeting. Then, the team traced raw audio transmitted from the apps. To the audio driver of the underlying OS, and eventually to the network.

This way, they can decide what changes really come up when a user presses ‘mute’. Also, they find that no matter the mute status. All apps periodically collect audio data, except for web clients that used the browser’s software mute feature. The apps sample audio on and off for many functional or unclear reasons in all other cases. Zoom, possibly the most popular video conferencing app worldwide. Was seems actively track if the user is talking even while they are in mute mode. Moreover, according to the study, the worst case was Cisco Webex. Which continued to receive raw audio data from the user’s microphone. And transmitted it to the vendor’s servers in the same way it did when unmuted. Hence, the mute button in conferencing apps is not gets mute in some situations.

However, “Our findings suggest that, contrary to the statement in the privacy policy, webex monitors. Collects, processes, and shares with its servers audio-derived data, while the user is on mute”. Reads the technical paper that supports the study. “To inform Cisco of our investigation results, we opened a responsible disclosure with Cisco about our findings. As of February 2022, their Webex engineering team and privacy team are actively working on solving this issue”. Therefore, even if the vendors secure their servers, encrypt data transmissions. And their employees abide by strict anti-abuse agreements. A man-in-the-middle attack might result in unexpected exposure for the target.

Though, remember, VCAs are use by high-ranking company executives, members of national security boards, and country-leading politicians. So data leaks while mute are active can be quite damaging. Thus, the mute button in conferencing apps does not work properly; it can be very dangerous for the legal prospectus.

What can you do?

Mute button in conferencing apps

First, read the privacy policy to understand better how your data is managed. And what risks are involved in using a particular software product.

Secondly, connect the microphone to your computer via a USB or jack cable, you may as well unplug it when muted.

Thirdly, you can use your OS’s audio control settings to mute your microphone’s input channel. So that any apps will receive zero volume audio.



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