This article is a great example why you should use your own router instead of ISP provided one
If this request worked, it meant that I could use an “encryptedValue” parameter in the API that didn’t have to have a matching account ID.
I sent the request and saw the exact same HTTP response as above! This confirmed that we didn’t need any extra parameters, we could just query any hardware device arbitrarily by just knowing the MAC address (something that we could retrieve by querying a customer by name, fetching their account UUID, then fetching all of their connected devices via their UUID). We now had essentially a full kill chain.
I formed the following HTTP request to update my own device MAC addresses SSID as a proof of concept to update my own hardware:
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Did it work? It had only given me a blank 200 OK response. I tried re-sending the HTTP request, but the request timed out. My network was offline. The update request must’ve reset my device.
About 5 minutes later, my network rebooted. The SSID name had been updated to “Curry”. I could write and read from anyone’s device using this exploit.
This demonstrated that the API calls to update the device configuration worked. This meant that an attacker could’ve accessed this API to overwrite configuration settings, access the router, and execute commands on the device. At this point, we had a similar set of permissions as the ISP tech support and could’ve used this access to exploit any of the millions of Cox devices that were accessible through these APIs.
Blows me a away that an unauthenticated API with sensitive controls and data was publicly facing. Corporations these days want all your data but wonder why some customers are worry about how it is protected, it let alone if it’s being sold. Why should I allow you to control my hardware when you can’t protect yourself.
Why should I allow you to control my hardware when you can’t protect yourself
Correction, they can protect themselves, but they chose not to devote the time, money and effort it would take to make sure they’re secure. They just slap it together asap, say good enough, and start charging millions of dollars for customers to use it
This was a really interesting read , Thanks for sharing
lol holy shit
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The only thing in the above parameter that was valid was the device serial number. If this request worked, it meant that I could use an “encryptedValue” parameter in the API that didn’t have to have a matching account ID.
I sent the request and saw the exact same HTTP response as above! This confirmed that we didn’t need any extra parameters, we could just query any hardware device arbitrarily by just knowing the MAC address (something that we could retrieve by querying a customer by name, fetching their account UUID, then fetching all of their connected devices via their UUID). We now had essentially a full kill chain.
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And then he proceeds to make arbitrary changes to his own modem via this exploit as a final proof. Jesus tapdancing christ.
I’m not a programmer but is it normal that the login page contains the whole main JavaScript code of a logged in user?
Also, what’s the point of having this kind of client side api? Because you can never trust the client shouldn’t be everything server side and only return a html page with the data related to your account?
It doesn’t matter that website loads javascript code for logged in user, as you need a token (which server will give you after a successful login) to authenticate to apis, it is pretty common to do that way
There wasn’t a client side API, but the API was missing crucial validation of user input (eg only checking the mac address but didn’t check who is actually authenticated)
What a great read! Thanks so much for sharing this.
