• 60 Posts
  • 1.75K Comments
Joined 3 years ago
Aquileo | cake
Cake day: June 7th, 2023

Aquileo | help-circle

  • Even when a company is doing things pretty well with a VPN, all it takes is one mistake and the cat is out of the bag. At one of my previous employers, we had a fairly good setup with VPNs using single sign on via our IdM provider. IdM enforced SSO and the VPN had a number of policies setup which kept good control over what users could login. And then someone had the brilliant idea to take an old VPN appliance, reset it to factory defaults and configure it just enough to work on our network and then hung it out on the internet for some sort of test (our configuration management left a lot to be desired). Of course, that led to it being left there for a couple months and an attacker finally found it. They also had a valid username/password combination which got them in the door.

    Security is hard and often expensive. But still, compared to “we put out OT devices on the internet” a basic VPN is a huge step up.




  • In absolute terms, there is probably some small increase in risk due to the NFC interface. As a practical attack, it’s probably not worth worrying about. Directly from the paper you linked:

    NB the term skimming for such an attack can be misleading if one thinks of well-known mag-stripe skimming of bank cards. When skimming mag-stripes, the attacker secretly reads the information on the mag-stripe, and can then make copies to create clones of the original bank card that cannot be distinguished from the original. For RFID tags, an attacker will not be able to create clones with a skimming attack, as long as the protocol uses some form of challenge-response.

    Which, the YubiKey, at least, used a challenge-response. While there is a known vulnerability which can be used to extract the internal secret and therefore clone a YubiKey 5, it requires long term physical access and is not trivial.

    The bigger concern for the NFC tag would be its use in a relay attack. And with a big enough antenna, an attacker might be able to do that. However, I would again point to the paper you linked to, their results were “long” for an RFID activation and read. But, not really all that long:

    a gate with a width of 100 cm, which can communicate with a tag held near the center between the two antenna

    And their setup required a couple large antennas that the victim would need to stand in between. Not impossible, but you’d notice with each side being half a meter away.

    So yes, it’s a technical risk, but not one that I’d bother putting much effort into avoiding. And the being able to use the key via NFC is probably worth the risk.















  • Are you really worried about the case where a thief steals the hard drive but not the rest of the computer?

    Even if the thief steals the entire computer, BitLocker/LUKS and SecureBoot provide a reasonable level of protection against data theft. Yes, the drive (or bits of it anyway) are automatically decrypted (the whole drive is never decrypted, just the data requested by the OS). However, it still prevents the attacker from accessing that data outside the intended operating system, which makes data theft much harder. An attacker would also need a valid account to login to the system to start accessing data. It’s not an insurmountable hurdle, but it does mean that just having the computer isn’t the same as having the data.

    Without encryption, once a thief has the computer, they have the data. They don’t need a valid account to access the data and they can even boot into a tool to reset passwords on the primary OS and start using it. Last I checked, chntpw still works with Windows 11. That sort of thing fails with encryption, even with TPM only. The TPM will not release the encryption key to an OS if SecureBoot fails. Granted, there is the YellowKey backdoor, but that was probably Microsoft giving the FBI a helping hand. But, that falls outside the intended design.