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 temporary physical access to it, researchers said Tuesday.
https://arstechnica.com/security/2024/09/yubikeys-are-vulnerable-to-cloning-attacks-thanks-to-newly-discovered-side-channel/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.