libu2f-host — security advisory
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.
- Products
- libu2f-host
- Affected versions
- Not specified
- Fixed versions
- 1.1.7-1
- CVEs
- CVE-2018-20340
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 01:33 UTC · Revision 1
Source evidence
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.
osv:DEBIAN-CVE-2018-20340
libu2f-host
Fixed versions: 1.1.7-1
libu2f-host
Fixed versions: 1.1.7-1
libu2f-host
Fixed versions: 1.1.7-1
Complete source record
{
"id": "c604b80c393cfbd8712b3d6eb483495aeb37c33581ce06d424633f10f5347d28",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2018-20340",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2018-20340",
"summary": "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.",
"evidence": "osv:DEBIAN-CVE-2018-20340",
"products": [
{
"name": {
"value": "libu2f-host",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.1.7-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libu2f-host",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.1.7-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libu2f-host",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.1.7-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2018-20340",
"aliases": [
"DEBIAN-CVE-2018-20340"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
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],
"package": {
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"purl": "pkg:deb/debian/libu2f-host?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-20340.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.1.7-1"
}
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}
],
"package": {
"name": "libu2f-host",
"purl": "pkg:deb/debian/libu2f-host?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-20340.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.1.7-1"
}
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}
],
"package": {
"name": "libu2f-host",
"purl": "pkg:deb/debian/libu2f-host?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-20340.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:04:47.815169723Z",
"provider": "osv",
"upstream": [
"CVE-2018-20340"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2018-20340"
]
},
"related_cves": [
{
"value": "CVE-2018-20340",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 423809,
"published_at": "2019-03-21T16:00:35.983+00:00"
}