Medium
Security advisory
An issue was discovered in FNET through 4.6.4. The code that initializes the DNS client interface structure does not set sufficiently random transaction IDs (they are always set to 1 in _fnet_dns_poll in fnet_dns.c). This significantly simplifies DNS cache poisoning attacks.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-17470
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 07:49 UTC · Revision 1
Source evidence
An issue was discovered in FNET through 4.6.4. The code that initializes the DNS client interface structure does not set sufficiently random transaction IDs (they are always set to 1 in _fnet_dns_poll in fnet_dns.c). This significantly simplifies DNS cache poisoning attacks.
osv:CVE-2020-17470
Complete source record
{
"id": "b661aace26c2c1906545f9063e1515d6da480d16f87a6aaf589fb10591b7a988",
"url": "https://osv.dev/vulnerability/CVE-2020-17470",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-17470",
"summary": "An issue was discovered in FNET through 4.6.4. The code that initializes the DNS client interface structure does not set sufficiently random transaction IDs (they are always set to 1 in _fnet_dns_poll in fnet_dns.c). This significantly simplifies DNS cache poisoning attacks.",
"evidence": "osv:CVE-2020-17470",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2020-17470",
"aliases": [
"CVE-2020-17470"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/butok/fnet",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"last_affected": "fdfcc63a5715b524ab1809fa67e9b939b5510325"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:butok:fnet:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"last_affected": "4.6.4"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v4.6.4",
"v4.6.3",
"v4.6.2",
"v4.6.1",
"v4.6.0",
"v4.5.3",
"v4.5.2",
"v4.5.1",
"v4.5.0",
"v4.4.1",
"v4.4.0",
"v4.3.0",
"v4.2.0",
"v4.1.1",
"v4.1.0",
"v4.0.2",
"v4.0.1",
"v4.0.0",
"v3.9.4",
"v3.9.3updated",
"v3.9.3prev",
"v3.9.3pre",
"v3.9.3",
"v3.9.2",
"v3.9.1",
"v3.9.0",
"v3.8.2",
"v3.8.1",
"v3.8.0",
"v3.7.0",
"v3.6.1",
"3.6.0",
"v3.5.0",
"v3.4.0",
"FNET_3.3.0",
"v3.2.0",
"3.1.1",
"v3.0.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-17470.json"
}
}
],
"modified": "2026-10-24T10:30:59.050384282Z",
"provider": "osv",
"references": [
"https://us-cert.cisa.gov/ics/advisories/icsa-20-343-01",
"https://www.kb.cert.org/vuls/id/815128"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2020-17470",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 439213,
"published_at": "2020-12-11T23:15:13.747+00:00"
}