HOMEVULNERABILITIESCVE-2020-10185
HIGH

CVE-2020-10185

CWE-294Published: March 5, 2020· Updated: Jun 17, 2026

8.6
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2020-10185 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 8.6.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityLow
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

Affected Vendors & Products

yubico1 product(s)
yubikey one time password validation server
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://github.com/Yubico/yubikey-val/releases/tag/yubikey-val-2.40
ADVISORYhttps://www.yubico.com/support/security-advisories/ysa-2020-01/
ADVISORYhttps://github.com/Yubico/yubikey-val/releases/tag/yubikey-val-2.40
ADVISORYhttps://www.yubico.com/support/security-advisories/ysa-2020-01/

All References (6)

→
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

Quick Facts

CVE IDCVE-2020-10185
CVSS Score8.6 / 10
SeverityHIGH
WeaknessCWE-294
CISA KEVNo
Affected1 vendor(s)
PublishedMar 5, 2020

Related CVEs (CWE-294)

CVE-2025-49752
10.0
CVE-2018-7790
9.8
CVE-2026-28564
9.8
CVE-2023-47435
9.8
CVE-2023-49231
9.8
CVE-2019-18226
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-10185 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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