squid — security advisory
An issue was discovered in Squid before 4.10. Due to incorrect input validation, the NTLM authentication credentials parser in ext_lm_group_acl may write to memory outside the credentials buffer. On systems with memory access protections, this can result in the helper process being terminated unexpectedly. This leads to the Squid process also terminating and a denial of service for all clients using the proxy.
- Products
- squid
- Affected versions
- Not specified
- Fixed versions
- 4.10-1
- CVEs
- CVE-2020-8517
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 13:20 UTC · Revision 1
Source evidence
An issue was discovered in Squid before 4.10. Due to incorrect input validation, the NTLM authentication credentials parser in ext_lm_group_acl may write to memory outside the credentials buffer. On systems with memory access protections, this can result in the helper process being terminated unexpectedly. This leads to the Squid process also terminating and a denial of service for all clients using the proxy.
osv:DEBIAN-CVE-2020-8517
squid
Fixed versions: 4.10-1
squid
Fixed versions: 4.10-1
squid
Fixed versions: 4.10-1
Complete source record
{
"id": "5a1ad250894537310909a71bbdb784ac7ffeb3e80076777b53a672877ee531be",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2020-8517",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2020-8517",
"summary": "An issue was discovered in Squid before 4.10. Due to incorrect input validation, the NTLM authentication credentials parser in ext_lm_group_acl may write to memory outside the credentials buffer. On systems with memory access protections, this can result in the helper process being terminated unexpectedly. This leads to the Squid process also terminating and a denial of service for all clients using the proxy.",
"evidence": "osv:DEBIAN-CVE-2020-8517",
"products": [
{
"name": {
"value": "squid",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.10-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "squid",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.10-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "squid",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.10-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2020-8517",
"aliases": [
"DEBIAN-CVE-2020-8517"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.10-1"
}
]
}
],
"package": {
"name": "squid",
"purl": "pkg:deb/debian/squid?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-8517.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.10-1"
}
]
}
],
"package": {
"name": "squid",
"purl": "pkg:deb/debian/squid?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-8517.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.10-1"
}
]
}
],
"package": {
"name": "squid",
"purl": "pkg:deb/debian/squid?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-8517.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
}
],
"modified": "2026-10-26T12:02:24.321831546Z",
"provider": "osv",
"upstream": [
"CVE-2020-8517"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2020-8517"
]
},
"related_cves": [
{
"value": "CVE-2020-8517",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 452110,
"published_at": "2020-02-04T20:15:14.857+00:00"
}