{"id":"CVE-2018-20340","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-20340","generatedAt":"2026-10-28T19:05:04.001Z","title":"Yubico libu2f-host 1.1.6 contains unchecked buffers in devs.c, which could enable a malicious token to exploit a buffer overflow.","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.","published":"2019-03-21T16:00:36.000Z","lastModified":"2026-06-17T01:52:39.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.0","score":6.8,"severity":"MEDIUM","vector":"CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-119"],"affected":["yubico/libu2f-host","debian/debian linux"],"epss":{"score":0.00499,"percentile":0.42575,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.50%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://blog.inhq.net/posts/yubico-libu2f-host-vuln-part1/","source":"cve@mitre.org"},{"url":"https://developers.yubico.com/libu2f-host/Release_Notes.html","tags":["Release Notes","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://seclists.org/bugtraq/2019/Feb/23","tags":["Mailing List","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://security.gentoo.org/glsa/202004-15","source":"cve@mitre.org"},{"url":"https://www.debian.org/security/2019/dsa-4389","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.yubico.com/support/security-advisories/ysa-2019-01/","tags":["Patch","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://blog.inhq.net/posts/yubico-libu2f-host-vuln-part1/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://developers.yubico.com/libu2f-host/Release_Notes.html","tags":["Release Notes","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://seclists.org/bugtraq/2019/Feb/23","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202004-15","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2019/dsa-4389","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.yubico.com/support/security-advisories/ysa-2019-01/","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-20340","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}