Some interesting research from my alma mater: you can somewhat reliably transmit covert voice-band frequencies toward popular home assistant devices that are near passband cutoff freqs.

Research paper:
https://web.archive.org/web/20230528045017/https://www.usenix.org/system/files/sec23fall-prepub-261-xia-qi.pdf

CVE:
https://nvd.nist.gov/vuln/detail/CVE-2023-33248

#utsa #infosec #covertchannel #homeassistant #amazon #amazonecho