High
nim — security advisory
Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4, "nimble refresh" fetches a list of Nimble packages over HTTPS without full verification of the SSL/TLS certificate due to the default setting of httpClient. An attacker able to perform MitM can deliver a modified package list containing malicious software packages. If the packages are installed and used the attack escalates to untrusted code execution.
- Products
- nim
- Affected versions
- 0.11.2+dfsg1-4, 0.12.0-2, 0.17.2-1ubuntu1, 0.17.2-1ubuntu2, 0.20.2-1, 1.0.2-1, 1.0.3~rc-1, 1.0.4-1, 1.0.6-1, 1.6.14-1, 1.6.14-1ubuntu1, 1.6.14-1ubuntu2, 2.2.10-1, 2.2.4-1, 2.2.4-2
- Fixed versions
- Not specified
- CVEs
- CVE-2021-21374
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 00:57 UTC · Revision 1
Source evidence
Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4, "nimble refresh" fetches a list of Nimble packages over HTTPS without full verification of the SSL/TLS certificate due to the default setting of httpClient. An attacker able to perform MitM can deliver a modified package list containing malicious software packages. If the packages are installed and used the attack escalates to untrusted code execution.
osv:UBUNTU-CVE-2021-21374
nim
Fixed versions: Not specified
nim
Fixed versions: Not specified
nim
Fixed versions: Not specified
nim
Fixed versions: Not specified
nim
Fixed versions: Not specified
nim
Fixed versions: Not specified
nim
Fixed versions: Not specified
Complete source record
{
"id": "d9a64a7b807ba8983b3c507d4940c35c63e40c4b7a34cf57be72b69a907e1954",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-21374",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2021-21374",
"summary": "Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4, \"nimble refresh\" fetches a list of Nimble packages over HTTPS without full verification of the SSL/TLS certificate due to the default setting of httpClient. An attacker able to perform MitM can deliver a modified package list containing malicious software packages. If the packages are installed and used the attack escalates to untrusted code execution.",
"evidence": "osv:UBUNTU-CVE-2021-21374",
"products": [
{
"name": {
"value": "nim",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.11.2+dfsg1-4",
"evidence": "/affected/0/versions"
},
{
"value": "0.12.0-2",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "nim",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.17.2-1ubuntu1",
"evidence": "/affected/1/versions"
},
{
"value": "0.17.2-1ubuntu2",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "nim",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.20.2-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.0.2-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.0.3~rc-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.0.4-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.0.6-1",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "nim",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.6.14-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.6.14-1ubuntu1",
"evidence": "/affected/3/versions"
},
{
"value": "1.6.14-1ubuntu2",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "nim",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.6.14-1ubuntu2",
"evidence": "/affected/4/versions"
},
{
"value": "2.2.4-1",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "nim",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.2.4-2",
"evidence": "/affected/5/versions"
},
{
"value": "2.2.10-1",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "nim",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.2.4-1",
"evidence": "/affected/6/versions"
},
{
"value": "2.2.4-2",
"evidence": "/affected/6/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2021-21374",
"aliases": [
"UBUNTU-CVE-2021-21374"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:L"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "nim",
"purl": "pkg:deb/ubuntu/nim?arch=source&distro=xenial",
"ecosystem": "Ubuntu:16.04:LTS"
},
"versions": [
"0.11.2+dfsg1-4",
"0.12.0-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21374.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "nim",
"binary_version": "0.12.0-2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "nim",
"purl": "pkg:deb/ubuntu/nim?arch=source&distro=bionic",
"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
"0.17.2-1ubuntu1",
"0.17.2-1ubuntu2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21374.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "nim",
"binary_version": "0.17.2-1ubuntu2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
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}
]
}
],
"package": {
"name": "nim",
"purl": "pkg:deb/ubuntu/nim?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"0.20.2-1",
"1.0.2-1",
"1.0.3~rc-1",
"1.0.4-1",
"1.0.6-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21374.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "nim",
"binary_version": "1.0.6-1"
}
]
}
},
{
"ranges": [
{
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}
],
"package": {
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"purl": "pkg:deb/ubuntu/nim?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"1.6.14-1",
"1.6.14-1ubuntu1",
"1.6.14-1ubuntu2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21374.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "nim",
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}
]
}
},
{
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],
"package": {
"name": "nim",
"purl": "pkg:deb/ubuntu/nim?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
"1.6.14-1ubuntu2",
"2.2.4-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21374.json"
},
"ecosystem_specific": {
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},
{
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],
"package": {
"name": "nim",
"purl": "pkg:deb/ubuntu/nim?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"2.2.4-2",
"2.2.10-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21374.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "nim",
"binary_version": "2.2.10-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
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],
"package": {
"name": "nim",
"purl": "pkg:deb/ubuntu/nim?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"2.2.4-1",
"2.2.4-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21374.json"
},
"ecosystem_specific": {
"binaries": [
{
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"binary_version": "2.2.4-2"
}
]
}
}
],
"modified": "2026-10-17T12:56:19.176233536Z",
"provider": "osv",
"upstream": [
"CVE-2021-21374"
],
"references": [
"https://ubuntu.com/security/CVE-2021-21374",
"https://consensys.net/diligence/vulnerabilities/nim-insecure-ssl-tls-defaults-remote-code-execution/",
"https://www.cve.org/CVERecord?id=CVE-2021-21374"
]
},
"related_cves": [
{
"value": "CVE-2021-21374",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 355244,
"published_at": "2021-03-26T22:15:00+00:00"
}