I recently discovered a similar concerning security issue with my KVM. In my case it was a pretty standard KVM for multiple machines to share a keyboard, mouse, and screen but also Ethernet. One day while looking at my home network I noticed the KVM had its own IP and was transferring GBs of data everyday. I quickly blocked it from my network. But having used it for a number of months I worried that with screen capture and access to all my input devices, someone could have gotten access to pretty much everything I use. I wasn’t able to figure out if any data was actually being sent off my network and I really didn’t want to put myself in any more risk so I just threw it in an electronics recycling bin. Pretty scary what a network connected KVM could maliciously do.
How I discovered a hidden microphone on a Chinese NanoKVM
11–20 of 138 posts
Re: How I discovered a hidden microphone on a Chinese NanoKVM
#12any speaker can be tapped into as a microphone by a motivated government.
No, because the drive circuit for a speaker is the opposite of the circuit for a microphone. The output stage of a speaker amplifier is just that, an output. The only way to record audio from a speaker, which is totally possible, is to have also purposely built an input stage also attached to the speaker. Which at that point you might as well just use a microphone...
Audio input and output are not reversible.
Re: How I discovered a hidden microphone on a Chinese NanoKVM
#13To be fair, the microphone _is_ listed on the specsheet of the LicheeRV Nano https://wiki.sipeed.com/hardware/en/lichee/RV_Nano/1_intro.h... I assume they didn't intend to put a mic on the KVM product, but they wanted to make a KVM product, already had this SBC product, which reusing their existing stock of helped keep cost low. Should they have been more up front about it it? Sure, and it's not great that they had a…
It doesn't strike me as that useful to have a hidden microphone in a KVM product as most of the time, they're going to be stuck in server rooms with just lots of fan noise to record.
Far more of an issue would be any kind of keylogger built into the software, which is why it's best to go for devices that support open source software.
Re: How I discovered a hidden microphone on a Chinese NanoKVM
#14To be fair, the microphone _is_ listed on the specsheet of the LicheeRV Nano https://wiki.sipeed.com/hardware/en/lichee/RV_Nano/1_intro.h... I assume they didn't intend to put a mic on the KVM product, but they wanted to make a KVM product, already had this SBC product, which reusing their existing stock of helped keep cost low. Should they have been more up front about it it? Sure, and it's not great that they had a…
It doesn't strike me as that useful to have a hidden microphone in a KVM product as most of the time, they're going to be stuck in server rooms with just lots of fan noise to record. Far more of an issue would be any kind of keylogger built into the software, which is why it's best to go for devices that support open source software.
It is possible to keylog via audio.
Re: How I discovered a hidden microphone on a Chinese NanoKVM
#15I recently discovered a similar concerning security issue with my KVM. In my case it was a pretty standard KVM for multiple machines to share a keyboard, mouse, and screen but also Ethernet. One day while looking at my home network I noticed the KVM had its own IP and was transferring GBs of data everyday. I quickly blocked it from my network. But having used it for a number of months I worried that with screen captu…
Shame you threw it away. It would have been useful to collect the traffic with Wireshark and share that with info about the device in a post or a blog for others to investigate and be warned about that brand and model.
Re: How I discovered a hidden microphone on a Chinese NanoKVM
#16Earlier quoted context omitted.
It doesn't strike me as that useful to have a hidden microphone in a KVM product as most of the time, they're going to be stuck in server rooms with just lots of fan noise to record. Far more of an issue would be any kind of keylogger built into the software, which is why it's best to go for devices that support open source software.
It is possible to keylog via audio. https://ieeexplore.ieee.org/abstract/document/10190721
But the point of a device like this is that you (and your keyboard) are NOT physically present.
Re: How I discovered a hidden microphone on a Chinese NanoKVM
#17I recently discovered a similar concerning security issue with my KVM. In my case it was a pretty standard KVM for multiple machines to share a keyboard, mouse, and screen but also Ethernet. One day while looking at my home network I noticed the KVM had its own IP and was transferring GBs of data everyday. I quickly blocked it from my network. But having used it for a number of months I worried that with screen captu…
Why did you not just login to the device, and switched off "Broadcast to multicast", or changed the destination address?
Edit: Some brands of Network-KVM use this, so that you can control the target device from another device, like e.g. an App on a tablet. That way you don't have to stand next to the target device in the noisy and cold machine room
Re: How I discovered a hidden microphone on a Chinese NanoKVM
#18Earlier quoted context omitted.
> But what additionally raised red flags was the presence of tcpdump and aircrack - tools commonly used for network packet analysis and wireless security testing. While these are useful for debugging and development, they are also hacking tools that can be dangerously exploited. Must be another AI slop article. Stop feeding your writings into GPT & co to turn into extra long nonsense.
What was wrong with the above paragraph?
Let's see:
1. It lacks systemd and apt.
systemd is so resource hungry that i'm sure they removed it to reduce the RAM bill. Apt... why install apt if the distro has a different means of updating?
2. While these are useful for debugging and development, they are also hacking tools that can be dangerously exploited.
This is purely fear mongering. Even the shell could be a "hacking tool that can be dangerously exploited". Let's remove the shell too.
There are some legitimate complaints in the article, like the use of the same key on all installs. The rest looks more like fear mongering and security theater.
Including the microphone. What were they supposed to do, desolder it manually and add $10 to the price of each device?
I don't see the article complaining that a PiKVM has so many unused peripherals when used as a KVM. To go in the spirit of item #2, the usb ports could be used as "dangerous hacking tools" so you should desolder your usb ports from a Pi used as a KVM, right?
Re: How I discovered a hidden microphone on a Chinese NanoKVM
#19any speaker can be tapped into as a microphone by a motivated government.
From a hardware point of view I've also noticed that speakers work like poor microphones (and LEDs like poor solar panels / light sensors), but is there any way to actually make this work on most devices without physically changing wiring? If the circuits aren't made to take measurements (or the software can't get at the readings) but only set a voltage on the wires, there wouldn't be a way to (ab)use this. I don't k…
I don’t think they meant literally “any” but more like a device with a speaker could be delivered to you that has a speaker/microphone. Like a Bluetooth speaker you order of the internet. It seems it would probably have to be personally targeted to you, but in that case, there are probably simpler ways.
Re: How I discovered a hidden microphone on a Chinese NanoKVM
#20What an amazing device, but also the price is incredible. This kind of device would have been such a game changer 15 to 20 years ago. Thank you for the detailed security analysis. At least the developers are responsive, that does seem like a green flag.