MediumFix available
squid — security advisory
Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server.
- Products
- squid
- Affected versions
- Not specified
- Fixed versions
- 4.13-10
- CVEs
- CVE-2021-33620
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 00:23 UTC · Revision 1
Source evidence
Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server.
osv:DEBIAN-CVE-2021-33620
squid
Fixed versions: 4.13-10
squid
Fixed versions: 4.13-10
squid
Fixed versions: 4.13-10
Complete source record
{
"id": "70ca1f41426e88550e2327ba503d56089b2a6897fb6278c0bb5a2796e0e5641b",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-33620",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2021-33620",
"summary": "Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server.",
"evidence": "osv:DEBIAN-CVE-2021-33620",
"products": [
{
"name": {
"value": "squid",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.13-10",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "squid",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.13-10",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "squid",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.13-10",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2021-33620",
"aliases": [
"DEBIAN-CVE-2021-33620"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.13-10"
}
]
}
],
"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-2021-33620.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.13-10"
}
]
}
],
"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-2021-33620.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.13-10"
}
]
}
],
"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-2021-33620.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:03:15.030469254Z",
"provider": "osv",
"upstream": [
"CVE-2021-33620"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-33620"
]
},
"related_cves": [
{
"value": "CVE-2021-33620",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 420954,
"published_at": "2021-05-28T12:15:07.697+00:00"
}