A new THaW paper was published at USENIX Security last week. It describes using a laser at a distance of 110 meters to stimulate audio sensors on smart speakers and thereby insert audio commands that are accepted as coming from a legitimate user. Techniques for dealing with this vulnerability are proposed.
Takeshi Sugawara, Benjamin Cyr, Sara Rampazzi, Daniel Genkin, and Kevin Fu. Light Commands: Laser-Based Audio Injection Attacks on Voice-Controllable Systems. In Proceedings of the USENIX Security Symposium (USENIX Security), pages 2631–2648, August 2020. USENIX Association.