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No exploitation reportedFix available

CVE-2018-20340

No exploitation reported by the sources we read.

  • Published2019-03-21
  • WeaknessCWE-119

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Yubico libu2f-host 1.1.6 contains unchecked buffers in devs.c, which could enable a malicious token to exploit a buffer overflow. An attacker could use this to attempt to execute malicious code using a crafted USB device masquerading as a security token on a computer where the affected library is currently in use. It is not possible to perform this attack with a genuine YubiKey.

Timeline

dates in UTC
  1. 2019-03-2116:00CVE publishedNVD

Versions per branch

NVD
Debian debian linux
BranchAffectedFixed in
9.0= 9.0no fix published
Yubico libu2f-host
BranchAffectedFixed in
1.1= 1.1.6no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • libu2f-hostUbuntu:18.04:LTSall versions · fixed in 1.1.4-1ubuntu0.1
  • libu2f-hostUbuntu:16.04:LTSall versions · no fixed version listed
  • libu2f-hostSUSE:Linux Enterprise Server for SAP Applications 12 SP4all versions · fixed in 1.1.6-3.5.1
  • libu2f-hostSUSE:Linux Enterprise Server 12 SP4all versions · fixed in 1.1.6-3.5.1
  • libu2f-hostSUSE:Linux Enterprise Module for Basesystem 15 SP3all versions · fixed in 1.1.10-3.9.1
  • libu2f-hostSUSE:Linux Enterprise Module for Basesystem 15 SP2all versions · fixed in 1.1.10-3.9.1
  • libu2f-hostSUSE:Linux Enterprise Module for Basesystem 15all versions · fixed in 1.1.6-3.3.3
  • libu2f-hostSUSE:Linux Enterprise Desktop 12 SP4all versions · fixed in 1.1.6-3.5.1

11 more package ranges on OSV.dev

Full record on NVD

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2019-03-21
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-rc58-rfcj-mcrr

Frequently asked questions

What is CVE-2018-20340?

Yubico libu2f-host 1.1.6 contains unchecked buffers in devs.c, which could enable a malicious token to exploit a buffer overflow. An attacker could use this to attempt to execute malicious code using a crafted USB device masquerading as a security token on a computer where the affected library is currently in use. It is not possible to perform this attack with a genuine YubiKey.

Is CVE-2018-20340 actively exploited?

Active exploitation of CVE-2018-20340 has not been confirmed. Its EPSS score was 0.5% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-20340?

CVE-2018-20340 has a CVSS v3 base score of 6.8 (MEDIUM severity), with vector string CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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