MediumFix available
upx-ucl — security advisory
A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.
- Products
- upx-ucl
- Affected versions
- Not specified
- Fixed versions
- 4.2.2-1
- CVEs
- CVE-2021-20285
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 00:18 UTC · Revision 1
Source evidence
A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.
osv:DEBIAN-CVE-2021-20285
upx-ucl
Fixed versions: 4.2.2-1
upx-ucl
Fixed versions: 4.2.2-1
Complete source record
{
"id": "9cfc4c1a4bc7e071a3c125f4a71443668656eaf31074fceec0e0b6dee6a9b3dd",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-20285",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2021-20285",
"summary": "A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.",
"evidence": "osv:DEBIAN-CVE-2021-20285",
"products": [
{
"name": {
"value": "upx-ucl",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.2.2-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "upx-ucl",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.2.2-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2021-20285",
"aliases": [
"DEBIAN-CVE-2021-20285"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.2.2-1"
}
]
}
],
"package": {
"name": "upx-ucl",
"purl": "pkg:deb/debian/upx-ucl?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-20285.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.2.2-1"
}
]
}
],
"package": {
"name": "upx-ucl",
"purl": "pkg:deb/debian/upx-ucl?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-20285.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
}
],
"modified": "2026-10-23T18:03:10.427897857Z",
"provider": "osv",
"upstream": [
"CVE-2021-20285"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-20285"
]
},
"related_cves": [
{
"value": "CVE-2021-20285",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 420683,
"published_at": "2021-03-26T17:15:13.14+00:00"
}