Yubico YubiKey 5 Series devices with firmware before 5.7.0 and YubiHSM 2 devices with firmware before 2.4.0 allow an ECDSA secret-key extraction attack (that requires physical access and expensive equipment) in which an electromagnetic side channel is present because of a non-constant-time modular inversion for the Extended Euclidean Algorithm, aka the EUCLEAK issue. Other uses of an Infineon cryptographic library may also be affected.

The PKCS11 module of the YubiHSM 2 SDK through 2023.01 does not properly validate the length of specific read operations on object metadata. This may lead to disclosure of uninitialized and previously used memory.

Incorrect access control in Yubico OTP functionality of the YubiKey hardware tokens along with the Yubico OTP validation server. The Yubico OTP supposedly creates hardware bound second factor credentials. When a user reprograms the OTP functionality by "writing" it on a token using the Yubico Personalization Tool, they can then upload the new configuration to Yubicos OTP validation servers. NOTE: the vendor disputes this because there is no way for a YubiKey device to prevent a user from deciding that a secret value, which is imported into the device, should also be stored elsewhere

Yubico ykneo-openpgp before 1.0.10 has a typo in which an invalid PIN can be used. When first powered up, a signature will be issued even though the PIN has not been validated.

The Yubico YubiHSM YubiHSM2 library 2021.08, included in the yubihsm-shell project, does not properly validate the length of some operations including SSH signing requests, and some data operations received from a YubiHSM 2 device.

Yubico pam-u2f before 1.1.1 has a logic issue that, depending on the pam-u2f configuration and the application used, could lead to a local PIN bypass. This issue does not allow user presence (touch) or cryptographic signature verification to be bypassed, so an attacker would still need to physically possess and interact with the YubiKey or another enrolled authenticator. If pam-u2f is configured to require PIN authentication, and the application using pam-u2f allows the user to submit NULL as the PIN, pam-u2f will attempt to perform a FIDO2 authentication without PIN. If this authentication is successful, the PIN requirement is bypassed.

An issue was discovered in the _send_secure_msg() function of Yubico yubihsm-shell through 2.0.3. The function does not correctly validate the embedded length field of an authenticated message received from the device because response_msg.st.len=8 can be accepted but triggers an integer overflow, which causes CRYPTO_cbc128_decrypt (in OpenSSL) to encounter an undersized buffer and experience a segmentation fault. The yubihsm-shell project is included in the YubiHSM 2 SDK product.

An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.

An issue was discovered in the _send_secure_msg() function of Yubico yubihsm-shell through 2.0.3. The function does not correctly validate the embedded length field of an authenticated message received from the device. Out-of-bounds reads performed by aes_remove_padding() can crash the running process, depending on the memory layout. This could be used by an attacker to cause a client-side denial of service. The yubihsm-shell project is included in the YubiHSM 2 SDK product.

An electromagnetic-wave side-channel issue was discovered on NXP SmartMX / P5x security microcontrollers and A7x secure authentication microcontrollers, with CryptoLib through v2.9. It allows attackers to extract the ECDSA private key after extensive physical access (and consequently produce a clone). This was demonstrated on the Google Titan Security Key, based on an NXP A7005a chip. Other FIDO U2F security keys are also impacted (Yubico YubiKey Neo and Feitian K9, K13, K21, and K40) as well as several NXP JavaCard smartcards (J3A081, J2A081, J3A041, J3D145_M59, J2D145_M59, J3D120_M60, J3D082_M60, J2D120_M60, J2D082_M60, J3D081_M59, J2D081_M59, J3D081_M61, J2D081_M61, J3D081_M59_DF, J3D081_M61_DF, J3E081_M64, J3E081_M66, J2E081_M64, J3E041_M66, J3E016_M66, J3E016_M64, J3E041_M64, J3E145_M64, J3E120_M65, J3E082_M65, J2E145_M64, J2E120_M65, J2E082_M65, J3E081_M64_DF, J3E081_M66_DF, J3E041_M66_DF, J3E016_M66_DF, J3E041_M64_DF, and J3E016_M64_DF).