CVE-2020-12061
📋 TL;DR
CVE-2020-12061 is a critical vulnerability in Nitrokey FIDO U2F firmware where communication between the microcontroller and secure element transmits credentials in plaintext. This allows attackers to eavesdrop on communications, extract stored secrets, and potentially manipulate the firmware. Users of Nitrokey FIDO U2F hardware security keys with firmware version 1.1 or earlier are affected.
💻 Affected Systems
- Nitrokey FIDO U2F
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the security key, allowing attacker to extract all stored credentials, impersonate the user, and potentially install malicious firmware.
Likely Case
Attacker with physical access or proximity can extract authentication secrets and clone the security key.
If Mitigated
With proper physical security controls, risk is limited to attackers with physical access to the device during use.
🎯 Exploit Status
Exploitation requires physical access or proximity to the device during operation. The vulnerability is well-documented in security research papers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware versions after 1.1
Vendor Advisory: https://github.com/Nitrokey/nitrokey-fido-u2f-firmware/releases
Restart Required: Yes
Instructions:
1. Download latest firmware from Nitrokey releases page. 2. Use Nitrokey's firmware update tool. 3. Follow device-specific flashing instructions. 4. Verify firmware version after update.
🔧 Temporary Workarounds
Physical Security Controls
allLimit physical access to devices and monitor for unauthorized device connections
🧯 If You Can't Patch
- Retire vulnerable devices and replace with updated hardware
- Implement additional authentication factors to reduce reliance on vulnerable keys
🔍 How to Verify
Check if Vulnerable:
Check firmware version using Nitrokey management software or command: nitrokey-fido2 statusCheck Version:
nitrokey-fido2 status | grep FirmwareVerify Fix Applied:
Verify firmware version is greater than 1.1 using device management tools📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts with security key
- Unexpected device connection/disconnection events
Network Indicators:
- Unusual USB device enumeration patterns
- Suspicious physical access to devices
SIEM Query:
DeviceLogs | where DeviceType == 'SecurityKey' and FirmwareVersion <= '1.1'🔗 References
- https://cwe.mitre.org/data/definitions/523.html
- https://eprint.iacr.org/2021/640.pdf
- https://github.com/Nitrokey/nitrokey-fido-u2f-firmware/commits/master
- https://github.com/Nitrokey/nitrokey-fido-u2f-firmware/releases
- https://cwe.mitre.org/data/definitions/523.html
- https://eprint.iacr.org/2021/640.pdf
- https://github.com/Nitrokey/nitrokey-fido-u2f-firmware/commits/master
- https://github.com/Nitrokey/nitrokey-fido-u2f-firmware/releases
