High
Security advisory
The web management console of CheckMK Enterprise Edition (versions 1.5.0 to 2.0.0p9) does not properly sanitise the uploading of ".mkp" files, which are Extension Packages, making remote code execution possible. Successful exploitation requires access to the web management interface, either with valid credentials or with a hijacked session of a user with administrator role. NOTE: the vendor states that this is the intended behavior: admins are supposed to be able to execute code in this manner.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2021-40905
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 04:33 UTC · Revision 1
Source evidence
The web management console of CheckMK Enterprise Edition (versions 1.5.0 to 2.0.0p9) does not properly sanitise the uploading of ".mkp" files, which are Extension Packages, making remote code execution possible. Successful exploitation requires access to the web management interface, either with valid credentials or with a hijacked session of a user with administrator role. NOTE: the vendor states that this is the intended behavior: admins are supposed to be able to execute code in this manner.
osv:CVE-2021-40905
Complete source record
{
"id": "474f8a03714f248539db2a3fcfc6feb97f1b038b3893ece95ff50e516e39e02d",
"url": "https://osv.dev/vulnerability/CVE-2021-40905",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2021-40905",
"summary": "The web management console of CheckMK Enterprise Edition (versions 1.5.0 to 2.0.0p9) does not properly sanitise the uploading of \".mkp\" files, which are Extension Packages, making remote code execution possible. Successful exploitation requires access to the web management interface, either with valid credentials or with a hijacked session of a user with administrator role. NOTE: the vendor states that this is the intended behavior: admins are supposed to be able to execute code in this manner.",
"evidence": "osv:CVE-2021-40905",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2021-40905",
"aliases": [
"CVE-2021-40905"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/checkmk/checkmk",
"type": "GIT",
"events": [
{
"introduced": "a08e390df0ae711bbee6fbdd0d32da1452918ae3"
},
{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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"source": "CPE_STRING"
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{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p2:*:*:*:*:*:*",
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"source": "CPE_STRING"
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{
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{
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"source": "CPE_STRING"
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{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:b4:*:*:*:*:*:*",
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{
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"source": "CPE_STRING"
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{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p4:*:*:*:*:*:*",
"range": [
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{
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"source": "CPE_STRING"
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{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:b5:*:*:*:*:*:*",
"range": [
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{
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"source": "CPE_STRING"
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{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p5:*:*:*:*:*:*",
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{
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}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:b6:*:*:*:*:*:*",
"range": [
{
"introduced": "2.0.0-b6"
},
{
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}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p6:*:*:*:*:*:*",
"range": [
{
"introduced": "2.0.0-p6"
},
{
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}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:b7:*:*:*:*:*:*",
"range": [
{
"introduced": "2.0.0-b7"
},
{
"last_affected": "2.0.0-b7"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p7:*:*:*:*:*:*",
"range": [
{
"introduced": "2.0.0-p7"
},
{
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}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:b8:*:*:*:*:*:*",
"range": [
{
"introduced": "2.0.0-b8"
},
{
"last_affected": "2.0.0-b8"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p8:*:*:*:*:*:*",
"range": [
{
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},
{
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],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p10:*:*:*:*:*:*",
"range": [
{
"introduced": "2.0.0-p10"
},
{
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}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p11:*:*:*:*:*:*",
"range": [
{
"introduced": "2.0.0-p11"
},
{
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}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p12:*:*:*:*:*:*",
"range": [
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},
{
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}
],
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},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p13:*:*:*:*:*:*",
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},
{
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}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p14:*:*:*:*:*:*",
"range": [
{
"introduced": "2.0.0-p14"
},
{
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}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p15:*:*:*:*:*:*",
"range": [
{
"introduced": "2.0.0-p15"
},
{
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}
],
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},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p16:*:*:*:*:*:*",
"range": [
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},
{
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}
],
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},
{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p17:*:*:*:*:*:*",
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{
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}
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{
"cpe": "cpe:2.3:a:checkmk:checkmk:2.0.0:p9:*:*:*:*:*:*",
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},
{
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}
],
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]
}
}
],
"versions": [
"2.0.0-NA",
"2.0.0-b1",
"2.0.0-b2",
"2.0.0-b3",
"2.0.0-b4",
"2.0.0-b5",
"2.0.0-b6",
"2.0.0-b7",
"2.0.0-b8",
"2.0.0-p10",
"2.0.0-p11",
"2.0.0-p12",
"2.0.0-p13",
"2.0.0-p14",
"2.0.0-p15",
"2.0.0-p16",
"2.0.0-p17",
"2.0.0-p9",
"v2.0.0p9",
"v2.0.0p8",
"v2.0.0p7",
"v2.0.0p6",
"v2.0.0p5",
"v2.0.0p4",
"v2.0.0p3",
"v2.0.0p1",
"v2.0.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-40905.json"
}
}
],
"modified": "2026-10-24T10:30:20.070213267Z",
"provider": "osv",
"references": [
"https://docs.checkmk.com/latest/en/mkps.html",
"https://github.com/Edgarloyola/CVE-2021-40905"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:a:tribe29:checkmk:*:*:*:*:*:*:*:*"
],
"vendor_product": "tribe29:checkmk",
"extracted_events": [
{
"range": [
{
"introduced": "1.5.0"
},
{
"fixed": "2.0.0"
}
],
"source": "CPE_RANGE"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2021-40905",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 430175,
"published_at": "2022-03-25T23:15:08.237+00:00"
}