e2guardian — security advisory
e2guardian v5.4.x <= v5.4.3r is affected by missing SSL certificate validation in the SSL MITM engine. In standalone mode (i.e., acting as a proxy or a transparent proxy), with SSL MITM enabled, e2guardian, if built with OpenSSL v1.1.x, did not validate hostnames in certificates of the web servers that it connected to, and thus was itself vulnerable to MITM attacks.
- Products
- e2guardian
- Affected versions
- Not specified
- Fixed versions
- 5.3.5-3
- CVEs
- CVE-2021-44273
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 01:09 UTC · Revision 1
Source evidence
e2guardian v5.4.x <= v5.4.3r is affected by missing SSL certificate validation in the SSL MITM engine. In standalone mode (i.e., acting as a proxy or a transparent proxy), with SSL MITM enabled, e2guardian, if built with OpenSSL v1.1.x, did not validate hostnames in certificates of the web servers that it connected to, and thus was itself vulnerable to MITM attacks.
osv:DEBIAN-CVE-2021-44273
e2guardian
Fixed versions: 5.3.5-3
e2guardian
Fixed versions: 5.3.5-3
e2guardian
Fixed versions: 5.3.5-3
Complete source record
{
"id": "79e283483ae52e0d10468ccc4fa3c02da130653bb4e4dbf4417c95b79483de75",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-44273",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2021-44273",
"summary": "e2guardian v5.4.x <= v5.4.3r is affected by missing SSL certificate validation in the SSL MITM engine. In standalone mode (i.e., acting as a proxy or a transparent proxy), with SSL MITM enabled, e2guardian, if built with OpenSSL v1.1.x, did not validate hostnames in certificates of the web servers that it connected to, and thus was itself vulnerable to MITM attacks.",
"evidence": "osv:DEBIAN-CVE-2021-44273",
"products": [
{
"name": {
"value": "e2guardian",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.3.5-3",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "e2guardian",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.3.5-3",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "e2guardian",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.3.5-3",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2021-44273",
"aliases": [
"DEBIAN-CVE-2021-44273"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.3.5-3"
}
]
}
],
"package": {
"name": "e2guardian",
"purl": "pkg:deb/debian/e2guardian?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-44273.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.3.5-3"
}
]
}
],
"package": {
"name": "e2guardian",
"purl": "pkg:deb/debian/e2guardian?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-44273.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.3.5-3"
}
]
}
],
"package": {
"name": "e2guardian",
"purl": "pkg:deb/debian/e2guardian?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-44273.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:04:17.155696041Z",
"provider": "osv",
"upstream": [
"CVE-2021-44273"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-44273"
]
},
"related_cves": [
{
"value": "CVE-2021-44273",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 423159,
"published_at": "2021-12-23T12:15:07.387+00:00"
}