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.
Scores
CVSS v3
8.6
EPSS
0.0059
EPSS Percentile
69.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
Details
CWE
CWE-294
Status
published
Products (1)
yubico/yubikey_one_time_password_validation_server
< 2.40
Published
Mar 05, 2020
Tracked Since
Feb 18, 2026