HighFix available
pure-ftpd — security advisory
In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, which may lead to denial of service or a server hang. This occurs because a certain greater-than-zero test does not anticipate an initial -1 value. (Versions 1.0.23 through 1.0.49 are affected.)
- Products
- pure-ftpd
- Affected versions
- Not specified
- Fixed versions
- 1.0.50-1
- CVEs
- CVE-2021-40524
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 23:57 UTC · Revision 1
Source evidence
In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, which may lead to denial of service or a server hang. This occurs because a certain greater-than-zero test does not anticipate an initial -1 value. (Versions 1.0.23 through 1.0.49 are affected.)
osv:DEBIAN-CVE-2021-40524
pure-ftpd
Fixed versions: 1.0.50-1
pure-ftpd
Fixed versions: 1.0.50-1
Complete source record
{
"id": "8dffeffad664496ebd8f28eb3f4c604cc5b2c3bbf1d77005bea13b0e7d692af5",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-40524",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2021-40524",
"summary": "In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, which may lead to denial of service or a server hang. This occurs because a certain greater-than-zero test does not anticipate an initial -1 value. (Versions 1.0.23 through 1.0.49 are affected.)",
"evidence": "osv:DEBIAN-CVE-2021-40524",
"products": [
{
"name": {
"value": "pure-ftpd",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.0.50-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "pure-ftpd",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.0.50-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2021-40524",
"aliases": [
"DEBIAN-CVE-2021-40524"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.0.50-1"
}
]
}
],
"package": {
"name": "pure-ftpd",
"purl": "pkg:deb/debian/pure-ftpd?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-40524.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.0.50-1"
}
]
}
],
"package": {
"name": "pure-ftpd",
"purl": "pkg:deb/debian/pure-ftpd?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-40524.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:02:30.745170160Z",
"provider": "osv",
"upstream": [
"CVE-2021-40524"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-40524"
]
},
"related_cves": [
{
"value": "CVE-2021-40524",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 419574,
"published_at": "2021-09-05T19:15:15.08+00:00"
}