CVE-2020-10185

Name: CVE-2020-10185
Creator: NVD / NIST
Published: 2020-03-05T23:15:13.353+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.6/10EPSS 1.45%

Last modified Jun 17, 2026

CVE-2020-10185 is a high-severity vulnerability rated 8.6/10 on the CVSS scale. The sync endpoint in YubiKey Validation Server before 2.40 allows remote attackers to replay an OTP. NOTE: this issue is potentially relevant to persons outside Yubico who operate a self-hosted OTP validation service with a non-default configuration such as an open sync pool; the issue does NOT affect YubiCloud.. EPSS estimates a 1.45% chance of exploitation in the next 30 days.

Description

The sync endpoint in YubiKey Validation Server before 2.40 allows remote attackers to replay an OTP. NOTE: this issue is potentially relevant to persons outside Yubico who operate a self-hosted OTP validation service with a non-default configuration such as an open sync pool; the issue does NOT affect YubiCloud.

Metrics

CVSS 3.1

8.6/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

EPSS Probability

1.45%

70.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-294

Affected Software

Vendor	Product	Versions
Yubico	Yubikey One Time Password Validation Server	< 2.40

References

https://github.com/Yubico/yubikey-val/releases/tag/yubikey-val-2.40Release Notes, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/03/msg00014.html
https://www.yubico.com/support/security-advisories/ysa-2020-01/Exploit, Vendor Advisory
https://github.com/Yubico/yubikey-val/releases/tag/yubikey-val-2.40Release Notes, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/03/msg00014.html
https://www.yubico.com/support/security-advisories/ysa-2020-01/Exploit, Vendor Advisory

Timeline

Published: Mar 5, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-10185?

How severe is CVE-2020-10185?

CVE-2020-10185 has a CVSS score of 8.6/10 (HIGH severity). The EPSS model estimates a 1.45% probability of exploitation in the next 30 days.

How do I fix CVE-2020-10185?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-10185?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST