The attacker would need physical possession of the YubiKey, Security Key, or YubiHSM, knowledge of the accounts they want to target and specialized equipment to perform the necessary attack. Depending on the use case, the attacker may also require additional knowledge including username, PIN, account password, or authentication key.
The attacks require about $11,000 worth of equipment and a sophisticated understanding of electrical and cryptographic engineering. The difficulty of the attack means it would likely be carried out only by nation-states or other entities with comparable resources and then only in highly targeted scenarios. The likelihood of such an attack being used widely in the wild is extremely low.
Given this massive caveat I’d almost call that headline misleading
Knowledge of the account is an obvious caveat. Yubikey-based MFA is an added layer of protection for accounts, so any kind of attack against MFA assumes the attacker already knows which account to target.
It’s like saying “our door lock is flawed, but the attacker would need to have knowledge of the door”.
The cost and complexity is what’s noteworthy and is more relevant. Although attack cost and complexity usuallu goes down with advances in tooling and research. So it may be a good idea to plan a progressive retirement of affected keys.
“Our door lock is flawed, but the attacker would need physical access to the key”
Cheaper just to beat you until you give them what they want.
I spent so much on these keys wth
Overrated…
Despite this affecting only FIDO and barely any Yubikeys are being used for that, it’s important to keep in mind that exploits and attacks get worse over time. For now it’s just FIDO and requires complex hardware and practically destroying the key. I wouldn’t be surprised if this exploit is just the beginning.
Is this because FIDO2 is flawed, the yubikey hardware design is flawed or both?
It’s due to a cryptographic library implementation in a controller used in the yubikey. It’s a third party controller, and this isn’t exclusive to yubikeys either, a shitload of other stuff uses the same controller and is likely vulnerable to the same attack.
Also, the attack requires around $10k worth of equipment and physical access to the yubikey, so while a valid attack vector, it’s also not something to get into a panic about.