Security News YubiKeys are vulnerable to cloning attacks thanks to newly discovered side channel

[Gandalf_The_Grey]

Content source

https://arstechnica.com/security/2024/09/yubikeys-are-vulnerable-to-cloning-attacks-thanks-to-newly-discovered-side-channel/

The YubiKey 5, the most widely used hardware token for two-factor authentication based on the FIDO standard, contains a cryptographic flaw that makes the finger-size device vulnerable to cloning when an attacker gains brief physical access to it, researchers said Tuesday.

The cryptographic flaw, known as a side channel, resides in a small microcontroller that’s used in a vast number of other authentication devices, including smartcards used in banking, electronic passports, and the accessing of secure areas. While the researchers have confirmed all YubiKey 5 series models can be cloned, they haven’t tested other devices using the microcontroller, which is the SLE78 made by Infineon and successor microcontrollers known as the Infineon Optiga Trust M and the Infineon Optiga TPM. The researchers suspect that any device using any of these three microcontrollers and the Infineon cryptographic library contains the same vulnerability.

YubiKey-maker Yubico issued an advisory in coordination with a detailed disclosure report from NinjaLab, the security firm that reverse-engineered the YubiKey 5 series and devised the cloning attack. All YubiKeys running firmware prior to version 5.7—which was released in May and replaces the Infineon cryptolibrary with a custom one—are vulnerable. Updating key firmware on the YubiKey isn’t possible. That leaves all affected YubiKeys permanently vulnerable.

“An attacker could exploit this issue as part of a sophisticated and targeted attack to recover affected private keys,” the advisory confirmed. “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.”

A key question that remains unanswered at the moment is what other security devices rely on the three vulnerable Infineon secure modules and use the Infineon cryptolibrary? Infineon has yet to issue an advisory and didn't respond to an email asking for one. At the moment, there is no known CVE for tracking the vulnerability.

YubiKeys are vulnerable to cloning attacks thanks to newly discovered side channel

Sophisticated attack breaks security assurances of the most popular FIDO key.

arstechnica.com

 

[R2D2]

I have a bunch of these Yubikey 5 keys (A/C/Nano) purchased in 2023 and now I see this. Anyway, the good thing is I am a very low profile bloke and this vulnerability does seem to be an exploit only State Actors or well funded groups would undertake. No wonder Yubikey released new keys with firmware version 5.7. They were obviously informed well in advance. Thing is will they hang us individual customers out to dry? Guess Corporates with large scale purchases get replacements.

 

[HarborFront]

I got the NFC 5C key which was purchased last year

I don't think it's easy to break as it requires to access the user's key and tear it down as detailed below

YubiKeys are vulnerable to cloning attacks thanks to newly discovered side channel

Sophisticated attack breaks security assurances of the most popular FIDO key.

arstechnica.com

Also, YubiKeys provide optional user authentication protections, including the requirement for a user-supplied PIN code or a fingerprint or face scan. For the cloning attack to work against YubiKeys using these additional measures, an attacker would need to possess the user verification factor as well. More information about using these additional measures to lock down YubiKeys further is available here.

So, for a home user I'll say it's still safe to use if the key has an earlier firmware version than v5.7

 

[R2D2]

It is still safe to use because:
a) The hacker needs to know your username and password
b) He needs physical access to your Yubikey
c) He needs time to clone the key whilst it's in his possession
d) Using a FIDO password can deter an attack to a large degree. My keys have always had a FIDO authentication password.
e) Last but not the least the $$ involved. Only groups with relatively deep pockets will attempt this and only if you are a target worth the time, money and effort.

TBH I am not overly worried about this issue. And yes I am a home user using these keys to protect my critical personal email and other accounts.

 

[SpiderWeb]

Saying that it costs a lot of money to use this vulnerability is not going to help me sleep better. The entire value proposition of security keys was that you can't do something like that and yet here we are. I'm definitely upgrading to new keys or a different company. Also Infineon is used in more than just Yubikey.

NinjaLab: "All Infineon security microcontrollers (including TPMs) that run the Infineon cryptographic library (as far as we know, any existing version) are vulnerable to the attack."

- Chips in e-passports from the US, China, India, Brazil and numerous European and Asian nations

- Secure enclaves in Samsung and OnePlus phones

- Cryptocurrency hardware wallets like Ledger and Trezor

- SIM cards

- TPMs in laptops from Lenovo, Dell, and HP

- EMV chips in credit and debit cards and car keys

Nevermind security keys. All modern Passports, credit cards, SIM cards and Samsung phones are screwed too. The attack vector is massive and it's just a matter of when until the tools to do it become more affordable.

 

[R2D2]

Here's a YT video by Lawrence Systems: Eucleak: Is Your Yubikey Still Secure?

 

[bazang]

So, for a home user I'll say it's still safe to use if the key has an earlier firmware version than v5.7

The Yubikeys with firmware prior to 5.7.0 are still safe to use. Even if someone has physical access to the key, it requires an extremely high level of sophisticated knowledge and experience to accomplish the attack. Specialized equipment and tools are needed too.

Yubikeys probably have more undiscovered vulnerabilities because of the same thing - few researchers possess the wherewithal to vuln hunt the devices.

While unfortunate that such a vuln exists, it is illogical to replace older keys with the vuln. I would not. The only exception is where I know I use a system targeted by nation-state threat actors and that system processes, stores or transmits data at a high sensitivity level.