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

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.001 (2.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 2.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-25201: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000

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.