civetweb — security advisory
The CivetWeb web library does not validate uploaded filepaths when running on an OS other than Windows, when using the built-in HTTP form-based file upload mechanism, via the mg_handle_form_request API. Web applications that use the file upload form handler, and use parts of the user-controlled filename in the output path, are susceptible to directory traversal
- Products
- civetweb
- Affected versions
- Not specified
- Fixed versions
- 1.15+dfsg-1
- CVEs
- CVE-2020-27304
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 13:48 UTC · Revision 1
Source evidence
The CivetWeb web library does not validate uploaded filepaths when running on an OS other than Windows, when using the built-in HTTP form-based file upload mechanism, via the mg_handle_form_request API. Web applications that use the file upload form handler, and use parts of the user-controlled filename in the output path, are susceptible to directory traversal
osv:DEBIAN-CVE-2020-27304
civetweb
Fixed versions: 1.15+dfsg-1
civetweb
Fixed versions: 1.15+dfsg-1
civetweb
Fixed versions: 1.15+dfsg-1
Complete source record
{
"id": "a5beb36904ad181a3bfbc669d80fc1219cfff229ae4f9cd9f79357bb09fa6558",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2020-27304",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2020-27304",
"summary": "The CivetWeb web library does not validate uploaded filepaths when running on an OS other than Windows, when using the built-in HTTP form-based file upload mechanism, via the mg_handle_form_request API. Web applications that use the file upload form handler, and use parts of the user-controlled filename in the output path, are susceptible to directory traversal",
"evidence": "osv:DEBIAN-CVE-2020-27304",
"products": [
{
"name": {
"value": "civetweb",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.15+dfsg-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "civetweb",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.15+dfsg-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "civetweb",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.15+dfsg-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "critical",
"structured": {
"id": "DEBIAN-CVE-2020-27304",
"aliases": [
"DEBIAN-CVE-2020-27304"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.15+dfsg-1"
}
]
}
],
"package": {
"name": "civetweb",
"purl": "pkg:deb/debian/civetweb?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-27304.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.15+dfsg-1"
}
]
}
],
"package": {
"name": "civetweb",
"purl": "pkg:deb/debian/civetweb?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-27304.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.15+dfsg-1"
}
]
}
],
"package": {
"name": "civetweb",
"purl": "pkg:deb/debian/civetweb?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-27304.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
}
],
"modified": "2026-10-26T12:02:42.518961967Z",
"provider": "osv",
"upstream": [
"CVE-2020-27304"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2020-27304"
]
},
"related_cves": [
{
"value": "CVE-2020-27304",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 452838,
"published_at": "2021-10-21T16:15:07.737+00:00"
}