High
upx-ucl — security advisory
Null pointer dereference was found in upx PackLinuxElf::canUnpack() in p_lx_elf.cpp,in version UPX 4.0.0. That allow attackers to execute arbitrary code and cause a denial of service via a crafted file.
- Products
- upx-ucl
- Affected versions
- 3.91-1, 3.94-2, 3.94-3, 3.94-4, 3.95-2, 3.95-2build1, 3.96-2, 3.96-3, 4.2.2-3, 4.2.4-1, 4.2.4-1.1, 4.2.4-1.1build1
- Fixed versions
- Not specified
- CVEs
- CVE-2021-30500
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 00:34 UTC · Revision 1
Source evidence
Null pointer dereference was found in upx PackLinuxElf::canUnpack() in p_lx_elf.cpp,in version UPX 4.0.0. That allow attackers to execute arbitrary code and cause a denial of service via a crafted file.
osv:UBUNTU-CVE-2021-30500
upx-ucl
Fixed versions: Not specified
upx-ucl
Fixed versions: Not specified
upx-ucl
Fixed versions: Not specified
upx-ucl
Fixed versions: Not specified
upx-ucl
Fixed versions: Not specified
upx-ucl
Fixed versions: Not specified
upx-ucl
Fixed versions: Not specified
upx-ucl
Fixed versions: Not specified
Complete source record
{
"id": "46d87483dfb6d62c35c39535b2805c9ed59c3b7c30e12d666852903060da4822",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-30500",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2021-30500",
"summary": "Null pointer dereference was found in upx PackLinuxElf::canUnpack() in p_lx_elf.cpp,in version UPX 4.0.0. That allow attackers to execute arbitrary code and cause a denial of service via a crafted file.",
"evidence": "osv:UBUNTU-CVE-2021-30500",
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"severity": "high",
"structured": {
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"aliases": [
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"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
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{
"type": "Ubuntu",
"score": "medium"
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"affected": [
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"package": {
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"purl": "pkg:deb/ubuntu/upx-ucl?arch=source&distro=xenial",
"ecosystem": "Ubuntu:16.04:LTS"
},
"versions": [
"3.91-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-30500.json"
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},
"versions": [
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],
"database_specific": {
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"database_specific": {
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"4.2.2-3"
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],
"modified": "2026-10-17T12:55:46.156905865Z",
"provider": "osv",
"upstream": [
"CVE-2021-30500"
],
"references": [
"https://ubuntu.com/security/CVE-2021-30500",
"https://github.com/upx/upx/issues/485",
"https://github.com/upx/upx/commit/90279abdfcd235172eab99651043051188938dcc",
"https://www.cve.org/CVERecord?id=CVE-2021-30500"
]
},
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"evidence": "/upstream"
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],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 354040,
"published_at": "2021-05-27T00:15:00+00:00"
}