High
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
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2021-30500
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 12:37 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:CVE-2021-30500
Complete source record
{
"id": "ff6496ad712ec2d2d90d05e42427f5250465b81dda08960858c5163ad83e1a65",
"url": "https://osv.dev/vulnerability/CVE-2021-30500",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "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:CVE-2021-30500",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2021-30500",
"aliases": [
"CVE-2021-30500"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/upx/upx",
"type": "GIT",
"events": [
{
"introduced": "69ca635c4c0ba474e9ca583dbb42e3d028c4533a"
},
{
"last_affected": "69ca635c4c0ba474e9ca583dbb42e3d028c4533a"
},
{
"fixed": "90279abdfcd235172eab99651043051188938dcc"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:upx:upx:4.0.0:*:*:*:*:*:*:*",
"range": [
{
"introduced": "4.0.0"
},
{
"last_affected": "4.0.0"
}
],
"source": "CPE_STRING"
},
{
"range": [
{
"fixed": "90279abdfcd235172eab99651043051188938dcc"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"versions": [
"4.0.0",
"v4.0.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-30500.json",
"vanir_signatures": [
{
"id": "CVE-2021-30500-1db58217",
"digest": {
"length": 187,
"function_hash": "195659927832214189917620206032031836622"
},
"source": "https://github.com/upx/upx/commit/90279abdfcd235172eab99651043051188938dcc",
"target": {
"file": "src/p_lx_elf.cpp",
"function": "PackLinuxElf32::canUnpack"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2021-30500-a331cfa2",
"digest": {
"length": 678,
"function_hash": "297660809110354721268824656352953698232"
},
"source": "https://github.com/upx/upx/commit/90279abdfcd235172eab99651043051188938dcc",
"target": {
"file": "src/p_lx_elf.cpp",
"function": "PackLinuxElf64::canUnpack"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2021-30500-e010c96c",
"digest": {
"threshold": 0.9,
"line_hashes": [
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},
"source": "https://github.com/upx/upx/commit/90279abdfcd235172eab99651043051188938dcc",
"target": {
"file": "src/p_lx_elf.cpp"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
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],
"vanir_signatures_modified": "2026-10-20T14:02:41Z"
}
}
],
"modified": "2026-10-20T14:02:41.628283299Z",
"provider": "osv",
"references": [
"https://bugzilla.redhat.com/show_bug.cgi?id=1948692",
"https://github.com/upx/upx/issues/485",
"https://github.com/upx/upx/commit/90279abdfcd235172eab99651043051188938dcc"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "33"
},
{
"last_affected": "33"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*"
],
"vendor_product": "redhat:enterprise_linux",
"extracted_events": [
{
"range": [
{
"introduced": "7.0"
},
{
"last_affected": "7.0"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2021-30500",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 388522,
"published_at": "2021-05-27T00:15:08.483+00:00"
}