5 ms·
Using ultrasound attack to disarm a smart-home system
- nier 4y agoThe article taught me that I can control Siri’s feedback volume by for example saying “Hey Siri, speak 25 percent.”
- karmaMeansCool 4y agoI learned that too, but now I'm wondering why her voice suddenly went silent a few weeks ago...
- bowmessage 4y agoI also experienced Siri talking at what seems like 1% volume recently, out of no change that I can recall making. Just learned how to fix that through these comments, thanks.
- jon-wood 4y agoThis has been driving me mad. It seems certain actions have had all audible feedback disabled, but there's no real sense to which ones. When I say across a room to set a reminder or add something to my shopping list my Homepods will just silently do so, with no indication but a flash of the screen. I have no idea if it's registered what I was saying or not. When I ask to turn on the lights in a room, it'll do a bing-bong noise at me to indicate that it's registered despite the fact I can see the lights turning on. It's utter nonsense.
- nier 4y agoMy guess is that the combination of a power button long-press continued by pressing the volume down button is something that might happen accidentally while you have the iPhone in your pocket. Once Siri is active, using the hardware volume buttons control the feedback volume.
- jon-wood 4y agoI had no idea about that. Quite tickled by it stopping and asking if I'm sure when I asked to speak at 100 percent.
- knodi123 4y agoWhy the heck wouldn't they have the wake-word listener confine itself to human-audible frequency ranges? Seems like that would be a really simple fix with zero loss of real-world functionality....
- jjeaff 4y agoThat's on purpose. They created a specific inaudible frequency that the Alexa listens for which causes it to ignore the wake word. This is how they keep from annoying everyone and also blowing up their own servers if, for example, they want to run an Alexa commercial during the Superbowl.
- tjoff 4y agoListening on inaudible words surely are not on purpose? Listening in on a frequency to disable word detection is a whole other thing...
- junon 4y ago> Reddit user aspyhackr may have figured out the trick Amazon uses here. Apparently, the Alexa commercials are intentionally muted in the 3,000Hz to 6,000Hz range of the audio spectrum, which apparently tips off the system that the “Alexa” phrase being spoken isn’t in fact a real command and should be ignored. Seems to be the inverse - if the wake word _lacks_ these frequencies, then Echos ignore it.
- jjeaff 4y agoYes, I had misremembered it. That does leave a mystery of why they are listening for inaudible frequency. I wonder if it might have to do with their plans of having devices that can connect to other connected devices when they aren't connected to the user's wifi.
- rjmunro 4y agoIt might be that although the sound is inaudible to humans, it gets distorted around and inside the device, and that distorted sound is at audible frequencies that the alexa microphone picks up. Something like how these ultrasonic directional speakers work: https://www.holosonics.com/what-makes-a-sound-source-directional https://www.holosonics.com/what-makes-a-sound-source-directi...
- thrdbndndn 4y ago> It's also worth noting that the length of malicious commands must be below 77 milliseconds — that's the average reaction time for the four voice assistants across multiple devices. I don't get it. Why? You can speak to smart assistants much longer than that isn't it?
- rblatz 4y agoThis har me confused at first too. Basically you are playing audio on the device and that audio will send a command to the same device. If I’m watching a video on my phone and say hey siri, it will interrupt the audio playing from my phone as it listens to me. But it isn’t instantly interrupting the audio, it apparently takes about 77 milliseconds.
- camtarn 4y agoAh I see, thank you!
- m_eiman 4y agoWhat I'm wondering is how a useful command can be expressed in 77 ms?
- stronglikedan 4y ago"weather"
- addisonl 4y ago> could be remotely hijacked, using carefully crafted near-ultrasonic sounds, and forced to make unwanted phone calls and money transfers, disable alarm systems, or unlock doors. I know Siri is much too dumb to facilitate a money transfer…
- Simon_O_Rourke 4y agoGetting Siri to actually do what you want it by standing close by and shouting tends not to work - not sure how some ultrasonic whisper is going to get the job done.
- jon-wood 4y agoAt least with Alexa devices disabling alarm systems and unlocking doors requires a PIN, mostly to defend against the much more low tech attack of shouting through the victim's letter box.
- yelling_cat 4y agoFor six months Siri interpreted my requests to call anyone as "Call Paul." It still might, but at that point I gave up and changed Paul's name in Contacts to stop accidentally bothering the poor guy.
- can16358p 4y agoThis makes me wonder if the research was inspired by the clever "prompt injection" attacks in the ChatGPT/LLM world (or vice versa).
- xnickb 4y agoOf course. And even the attack itself was proposed by chatgpt.
- Jnr 4y agoI simply do not expose critical switches to Siri from Home Assistant.
- midasuni 4y agoI only have Siri kick in when I press the button.
- pcardoso 4y agoI disabled it after a very potentially awkward event. I was talking to my wife while Siri on my Apple Watch misunderstood me, triggered itself and sent a text saying "I love you" to our previous maid (which we had fired because of reasons).
- thedanbob 4y agoYears ago a classmate in college was showing Siri to one of our teachers. As a joke he said "Siri, I love you!" and Siri replied "I'm sorry, I can't find a location for <teacher's daughter>".
- amelius 4y agoThey tried this before on a smart-hotel in Havana.
- IndySun 4y agoQuite sure the microphones on any smart speaker or phone do not have the build quality to 'hear' near ultrasonic audio.
- typedef_struct 4y agoPhreaking is back?
- doubled112 4y agoWill the right frequencies in the right order get me free Amazon delivery?
- BeefWellington 4y agoReminds me of this from a couple years ago where researchers figured out they could use lasers to do the same thing: https://cse.engin.umich.edu/stories/researchers-take-control-of-siri-alexa-and-google-home-with-lasers https://cse.engin.umich.edu/stories/researchers-take-control...
- crazygringo 4y agoThis doesn't make any sense to me. Why would voice recognition software be interpreting ultrasonic (or near-ultrasonic) signals at all? First, it doesn't make sense they'd be trained on them. So why would models be interpreting these as speech at all? And second, it doesn't make sense they'd make it from the microphone to the recognition engine -- surely there's a low pass filter in there to remove all extraneous noise above the vocal range? I don't get it. (Edit: could it be some kind of downsampling aliasing artifact that is interpreted as normal vocal frequency, precisely because they skip a low pass filter that would prevent it?)