MediumFix available
putty — security advisory
PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client).
- Products
- putty
- Affected versions
- Not specified
- Fixed versions
- 0.74-1
- CVEs
- CVE-2020-14002
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 12:42 UTC · Revision 1
Source evidence
PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client).
osv:DEBIAN-CVE-2020-14002
putty
Fixed versions: 0.74-1
putty
Fixed versions: 0.74-1
putty
Fixed versions: 0.74-1
Complete source record
{
"id": "db7e371960d9ba222edf86922268b3a81fce52a6fd3304c1ea32372dc6de4a7c",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2020-14002",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2020-14002",
"summary": "PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client).",
"evidence": "osv:DEBIAN-CVE-2020-14002",
"products": [
{
"name": {
"value": "putty",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "0.74-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "putty",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "0.74-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "putty",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "0.74-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2020-14002",
"aliases": [
"DEBIAN-CVE-2020-14002"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "0.74-1"
}
]
}
],
"package": {
"name": "putty",
"purl": "pkg:deb/debian/putty?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-14002.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "0.74-1"
}
]
}
],
"package": {
"name": "putty",
"purl": "pkg:deb/debian/putty?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-14002.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "0.74-1"
}
]
}
],
"package": {
"name": "putty",
"purl": "pkg:deb/debian/putty?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-14002.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-26T12:00:40.894818209Z",
"provider": "osv",
"upstream": [
"CVE-2020-14002"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2020-14002"
]
},
"related_cves": [
{
"value": "CVE-2020-14002",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 451264,
"published_at": "2020-06-29T18:15:11.767+00:00"
}