Auth bypass in Nitrokey Nitrokey-3-Firmware

CVE-2025-25201

Nitrokey 3 Firmware is the the firmware of Nitrokey 3 USB keys. For release 1.8.0, and test releases with PIV enabled prior to 1.8.0, the PIV application could accept invalid keys for authentication of the admin key. This could lead to compromise of the integrity of the data stored in the application. An attacker without access to the proper administration key would be able to generate new keys and overwrite certificates. Such an attacker would not be able to read-out or extract existing private data, nor would they be able to gain access to cryptographic operations that would normally require PIN-based authentication. The issue is fixed in piv-authenticator 0.3.9, and in Nitrokey's firmware 1.8.1.

Vulnerability class: Broken Authentication

EPSS: 0.001 (3.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.0 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-25201?
CVE-2025-25201 is a medium-severity vulnerability in Nitrokey Nitrokey-3-Firmware, classified under Improper Authentication. CVSS score: 4.0/10. Published 2025-02-12.
How severe is CVE-2025-25201?
Medium severity. CVSS v3 base score is 4.0 out of 10.