apache-log4j2 — security advisory
Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups. This allows an attacker with control over Thread Context Map data to cause a denial of service when a crafted string is interpreted. This issue was fixed in Log4j 2.17.0, 2.12.3, and 2.3.1.
- Products
- apache-log4j2
- Affected versions
- Not specified
- Fixed versions
- 2.17.0-1
- CVEs
- CVE-2021-45105
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 01:00 UTC · Revision 1
Source evidence
Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups. This allows an attacker with control over Thread Context Map data to cause a denial of service when a crafted string is interpreted. This issue was fixed in Log4j 2.17.0, 2.12.3, and 2.3.1.
osv:DEBIAN-CVE-2021-45105
apache-log4j2
Fixed versions: 2.17.0-1
apache-log4j2
Fixed versions: 2.17.0-1
apache-log4j2
Fixed versions: 2.17.0-1
Complete source record
{
"id": "d9baad37ba38fe75f3be4b0e507bc9995a8c52715e2d30b87fdbc5016a00beda",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-45105",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2021-45105",
"summary": "Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups. This allows an attacker with control over Thread Context Map data to cause a denial of service when a crafted string is interpreted. This issue was fixed in Log4j 2.17.0, 2.12.3, and 2.3.1.",
"evidence": "osv:DEBIAN-CVE-2021-45105",
"products": [
{
"name": {
"value": "apache-log4j2",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.17.0-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "apache-log4j2",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.17.0-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "apache-log4j2",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.17.0-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2021-45105",
"aliases": [
"DEBIAN-CVE-2021-45105"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.17.0-1"
}
]
}
],
"package": {
"name": "apache-log4j2",
"purl": "pkg:deb/debian/apache-log4j2?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-45105.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.17.0-1"
}
]
}
],
"package": {
"name": "apache-log4j2",
"purl": "pkg:deb/debian/apache-log4j2?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-45105.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.17.0-1"
}
]
}
],
"package": {
"name": "apache-log4j2",
"purl": "pkg:deb/debian/apache-log4j2?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-45105.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:04:00.973998023Z",
"provider": "osv",
"upstream": [
"CVE-2021-45105"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-45105"
]
},
"related_cves": [
{
"value": "CVE-2021-45105",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 422949,
"published_at": "2021-12-18T12:15:07.433+00:00"
}