UnratedFix available
apache2 — security advisory
The log_cookie function in mod_log_config.c in the mod_log_config module in the Apache HTTP Server 2.2.17 through 2.2.21, when a threaded MPM is used, does not properly handle a %{}C format string, which allows remote attackers to cause a denial of service (daemon crash) via a cookie that lacks both a name and a value.
- Products
- apache2
- Affected versions
- Not specified
- Fixed versions
- 2.2.22-1
- CVEs
- CVE-2012-0021
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 22:46 UTC · Revision 1
Source evidence
The log_cookie function in mod_log_config.c in the mod_log_config module in the Apache HTTP Server 2.2.17 through 2.2.21, when a threaded MPM is used, does not properly handle a %{}C format string, which allows remote attackers to cause a denial of service (daemon crash) via a cookie that lacks both a name and a value.
osv:DEBIAN-CVE-2012-0021
apache2
Fixed versions: 2.2.22-1
apache2
Fixed versions: 2.2.22-1
apache2
Fixed versions: 2.2.22-1
Complete source record
{
"id": "e2d9f28b9c0dd96793cdf6a7e66b562645b3d1522a34e517f00a4723b510afa8",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2012-0021",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2012-0021",
"summary": "The log_cookie function in mod_log_config.c in the mod_log_config module in the Apache HTTP Server 2.2.17 through 2.2.21, when a threaded MPM is used, does not properly handle a %{}C format string, which allows remote attackers to cause a denial of service (daemon crash) via a cookie that lacks both a name and a value.",
"evidence": "osv:DEBIAN-CVE-2012-0021",
"products": [
{
"name": {
"value": "apache2",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.2.22-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "apache2",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.2.22-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "apache2",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.2.22-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "DEBIAN-CVE-2012-0021",
"aliases": [
"DEBIAN-CVE-2012-0021"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.2.22-1"
}
]
}
],
"package": {
"name": "apache2",
"purl": "pkg:deb/debian/apache2?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2012-0021.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.2.22-1"
}
]
}
],
"package": {
"name": "apache2",
"purl": "pkg:deb/debian/apache2?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2012-0021.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.2.22-1"
}
]
}
],
"package": {
"name": "apache2",
"purl": "pkg:deb/debian/apache2?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2012-0021.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T17:47:29.215286864Z",
"provider": "osv",
"upstream": [
"CVE-2012-0021"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2012-0021"
]
},
"related_cves": [
{
"value": "CVE-2012-0021",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 417194,
"published_at": "2012-01-28T04:05:00.75+00:00"
}