LowFix available
unzip — security advisory
A flaw was found in unzip. The vulnerability occurs due to improper handling of Unicode strings, which can lead to a null pointer dereference. This flaw allows an attacker to input a specially crafted zip file, leading to a crash or code execution.
- Products
- unzip
- Affected versions
- Not specified
- Fixed versions
- 6.0-r11
- CVEs
- CVE-2021-4217
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 22:07 UTC · Revision 1
Source evidence
A flaw was found in unzip. The vulnerability occurs due to improper handling of Unicode strings, which can lead to a null pointer dereference. This flaw allows an attacker to input a specially crafted zip file, leading to a crash or code execution.
osv:ALPINE-CVE-2021-4217
unzip
Fixed versions: 6.0-r11
unzip
Fixed versions: 6.0-r11
unzip
Fixed versions: 6.0-r11
unzip
Fixed versions: 6.0-r11
unzip
Fixed versions: 6.0-r11
unzip
Fixed versions: 6.0-r11
unzip
Fixed versions: 6.0-r11
unzip
Fixed versions: 6.0-r11
Complete source record
{
"id": "02051e48412f0e89f14367a630ddb89c571c3c78b260ddb19f06d1e43f7bbfa5",
"url": "https://osv.dev/vulnerability/ALPINE-CVE-2021-4217",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "ALPINE-CVE-2021-4217",
"summary": "A flaw was found in unzip. The vulnerability occurs due to improper handling of Unicode strings, which can lead to a null pointer dereference. This flaw allows an attacker to input a specially crafted zip file, leading to a crash or code execution.",
"evidence": "osv:ALPINE-CVE-2021-4217",
"products": [
{
"name": {
"value": "unzip",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.0-r11",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "unzip",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.0-r11",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "unzip",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.0-r11",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "unzip",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.0-r11",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "unzip",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.0-r11",
"evidence": "/affected/4/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "unzip",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.0-r11",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "unzip",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
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"evidence": "/affected/6/ranges"
}
],
"affected_versions": []
},
{
"name": {
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"evidence": "/affected/7/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.0-r11",
"evidence": "/affected/7/ranges"
}
],
"affected_versions": []
}
],
"severity": "low",
"structured": {
"id": "ALPINE-CVE-2021-4217",
"aliases": [
"ALPINE-CVE-2021-4217"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.0-r11"
}
]
}
],
"package": {
"name": "unzip",
"purl": "pkg:apk/alpine/unzip?arch=source",
"ecosystem": "Alpine:v3.17"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-4217.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
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"events": [
{
"introduced": "0"
},
{
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}
]
}
],
"package": {
"name": "unzip",
"purl": "pkg:apk/alpine/unzip?arch=source",
"ecosystem": "Alpine:v3.18"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-4217.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
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"events": [
{
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},
{
"fixed": "6.0-r11"
}
]
}
],
"package": {
"name": "unzip",
"purl": "pkg:apk/alpine/unzip?arch=source",
"ecosystem": "Alpine:v3.19"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-4217.json"
},
"ecosystem_specific": {}
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{
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]
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],
"package": {
"name": "unzip",
"purl": "pkg:apk/alpine/unzip?arch=source",
"ecosystem": "Alpine:v3.20"
},
"database_specific": {
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},
"ecosystem_specific": {}
},
{
"ranges": [
{
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"events": [
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}
]
}
],
"package": {
"name": "unzip",
"purl": "pkg:apk/alpine/unzip?arch=source",
"ecosystem": "Alpine:v3.21"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-4217.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
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"events": [
{
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},
{
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}
]
}
],
"package": {
"name": "unzip",
"purl": "pkg:apk/alpine/unzip?arch=source",
"ecosystem": "Alpine:v3.22"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-4217.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
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}
]
}
],
"package": {
"name": "unzip",
"purl": "pkg:apk/alpine/unzip?arch=source",
"ecosystem": "Alpine:v3.23"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-4217.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
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}
]
}
],
"package": {
"name": "unzip",
"purl": "pkg:apk/alpine/unzip?arch=source",
"ecosystem": "Alpine:v3.24"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-4217.json"
},
"ecosystem_specific": {}
}
],
"modified": "2026-10-23T17:17:56.217346722Z",
"provider": "osv",
"upstream": [
"CVE-2021-4217"
],
"references": [
"https://security.alpinelinux.org/vuln/CVE-2021-4217"
]
},
"related_cves": [
{
"value": "CVE-2021-4217",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 415573,
"published_at": "2022-08-24T16:15:10.09+00:00"
}