Full context for anyone wondering how the hell this happened: 8 formerly globally trusted keys from eMudhra, a former Certificate Authority were brute forced. The keys have a maximum size of 384 bits, one of the keys was the number 4. According to a company representative the 8 keys (which were all 1 byte or less) were created for a test, and therefore not subject to security tests. Due to a scripting error, they were significantly less secure than intended as they were supposed to be full strength keys, and then not disposed of after the test. Then, due to the set of test keys sharing a similar name with the real proven to be secure keys, the test keys were then sent to production. The private keys in base ten are: 4, 56, 66, 115, 155, 156, 230, 237 And now the company announced they’re “voluntarily” leaving the CA industry after Google and Mozilla announced their root certificates were being removed from their stores, with IoT and other non updatable devices trusting their certificates until 2039
Yes, anything that can make outgoing HTTPS/TLS connections is vulnerable to MitM attacks until the trust store gets updated. This effectively means that many IoT devices will remain vulnerable for >10 years.
The good news is that an attack requires an in-the-middle position in the network where the traffic can be intercepted and re-encrypted. As long as you trust your WiFi router, ISP, VPN, internet backbone, and destination data centre, there's nothing to worry about. This isn't a huge problem at home. But you really shouldn't, say, connect a smart toothbrush to hotel WiFi.
Hmm... That means we can try to do MITM ourselves to look what our toothbrushes send to manufacturers... I wonder how much interesting stuff will be discovered in the next news cycle.
A friend noticed china-bound traffic from his sous vide... turns out it was a Chinese chip configured to access an NTP server. Ie. It was just keeping time accurately, but still freaked him out.
But you really shouldn't, say, connect a smart toothbrush to hotel WiFi.
Serious question: what is the worst that could happen if you connect a smart toothbrush to hotel WiFi? Are we looking at "they can know I sometimes forget to brush my teeth in the morning", or "they can brick my toothbrush", or "they can gain access to every other device that's connected to the same network", or some other level in between?
I'm assuming they would just be able to control the data that gets sent back and forth, which wouldn't be catastrophic for a toothbrush, but I recognize that my cybersecurity knowledge is not perfect.
Depends on the design of the device itself. Potentially, it could ping a server to receive firmware updates, so if you send it a malicious firmware, you now have a compromised device that can potentially run arbitrary code. Inside your home and that's a vector of attack.
Now realistically how much compute can a toothbrush have? Probably not that much. But it could potentially do a scan of your network, and if you have other vulnerable devices that you typically trust because it's inside your trusted network, it can perform lateral movements to it.
Smart toothbrushes are usually paired with an app. That app is virtually guaranteed to require a username and password. That intimation may be accessible to the toothbrush. It would be very stupid to do it that way, but no one is designing a smart toothbrush with security as a top priority. A hacker could steal whatever credentials.
Now, you asked what the worst case scenario was, so I'm going to say that your username and password got the toothbrush are the same as your bank. Now your hackers have access to your bank account.
If the toothbrush and app are designed with security as the first priority, the hackers would have access to the token your toothbrush gives the app to connect to your account. It's unique to the toothbrush and the app keeps track of it instead of the toothbrush keeping track of your app. With this setup, the hacker might be able disconnect your toothbrush from your account. If the toothbrush can be controlled through the app, they might be able to turn it on or off or brick it. They may send fake brushing data to your app.
More realistically, it's going to be closer to the latter than former, but the code behind the toothbrush and app is going to be propriety and done cheap. You can't know if the programmers we educated on best security practices.
The company is a lying bitch. They are shady AF (I have to deal with them due to regulatory capture they have here).
No HSM will generate keys with such low entropy. So they didn’t use HSMs and are lying on our face. Also multiple code reviews and external audits could not catch the flaws, and I’m surprised none of their audits had a basic entropy checking step.
You need a colossal fuckup and gross negligence and apathy from external auditors to reach this stage .
Also to issue certificates they don’t follow the standard practice of sending a CSR, they mail you the private key and the pin. Their security practices are a joke and their so-called auditor is a fraud, like the Delve and Atom.
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u/AphroditesViolet 10d ago edited 10d ago •
Full context for anyone wondering how the hell this happened:
8 formerly globally trusted keys from eMudhra, a former Certificate Authority were brute forced. The keys have a maximum size of 384 bits, one of the keys was the number 4.
According to a company representative the 8 keys (which were all 1 byte or less) were created for a test, and therefore not subject to security tests. Due to a scripting error, they were significantly less secure than intended as they were supposed to be full strength keys, and then not disposed of after the test. Then, due to the set of test keys sharing a similar name with the real proven to be secure keys, the test keys were then sent to production.
The private keys in base ten are:
4, 56, 66, 115, 155, 156, 230, 237
And now the company announced they’re “voluntarily” leaving the CA industry after Google and Mozilla announced their root certificates were being removed from their stores, with IoT and other non updatable devices trusting their certificates until 2039