The key facts

  • Glass-break sensors are based on a highly sensitive microphone, which is not always listed in the device's specifications
  • The threat arises when the sensor is connected to an internet hub: by hacking it, an attacker can activate the microphone remotely
  • Recommendations: a separate network for smart devices, firmware updates, strong passwords, reputable manufacturers

A microphone that isn't mentioned in the specs

Sergey Shcherbakov, Technical Director of the company Stakhanovets, in a conversation with Gazeta.Ru explained how acoustic glass-break sensors work and the risks associated with them. According to him, the operation of most such sensors is based on a highly sensitive microphone whose task is to detect the specific sound of breaking glass and ignore other noises. This means that a device purchased to protect an apartment effectively contains a permanently installed microphone whose presence the buyer may not even suspect.

A known precedent and the mechanism of the threat

The expert referred to a scandal involving the security system of one major manufacturer: a microphone was found in a device marketed as a motion sensor, although it was not listed in the official specifications. The manufacturer attributed this to an error and stated that the microphone was intended for a future glass-break detection feature. The microphone itself, in Shcherbakov's assessment, is merely a tool: the threat arises when the sensor gains access to the network. The sensor is usually connected to a central hub that is connected to the internet, and it is precisely this chain that creates the vulnerability. Having gained access to the hub — through a weak password, a firmware vulnerability, or a phishing attack — an attacker can not only disable the sensor but also remotely activate the microphone to record and transmit audio from the apartment.

Risks not only from private individuals and protective measures

Shcherbakov noted that the threat comes not only from private individuals: malicious software can be embedded in a device at the manufacturing stage, and manufacturers sometimes leave hidden access points for technical support that third parties could exploit. To reduce the risks, he recommended segmenting the network by allocating a separate wireless network for smart devices, regularly updating firmware, using strong passwords, and choosing reputable manufacturers. 'The problem lies not in the microphone itself, but in the possibility of gaining unauthorized access to it. Treat every smart home device as a potentially vulnerable computing node,' the expert concluded. The material supplements an earlier Gazeta.Ru publication in which an engineer explained how the security of smart devices actually works.