CVE-2021-22969
Concrete CMS (formerly concrete5) versions below 8.5.7 has a SSRF mitigation bypass using DNS Rebind attack giving an attacker the ability to fetch cloud IAAS (ex AWS) IAM keys.To fix this Concrete CMS no longer allows downloads from the local network and specifies the validated IP when downloading rather than relying on DNS.Discoverer: Adrian Tiron from FORTBRIDGE ( https://www.fortbridge.co.uk/ )The Concrete CMS team gave this a CVSS 3.1 score of 3.5 AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N . Please note that Cloud IAAS provider mis-configurations are not Concrete CMS vulnerabilities. A mitigation for this vulnerability is to make sure that the IMDS configurations are according to a cloud provider's best practices.This fix is also in Concrete version 9.0.0
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- Puntuación base: 5.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.86%
- Percentil entre todas las CVEs puntuadas: 57
- Fecha de la puntuación: 7/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-918
- CWE-918
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2021-22969",
"cveTags": [],
"metrics": {
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 5,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:L/Au:N/C:P/I:N/A:N",
"authentication": "NONE",
"integrityImpact": "NONE",
"accessComplexity": "LOW",
"availabilityImpact": "NONE",
"confidentialityImpact": "PARTIAL"
},
"acInsufInfo": false,
"impactScore": 2.9,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 10,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": false
}
],
"cvssMetricV31": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 5.3,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "LOW"
},
"impactScore": 1.4,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "support@hackerone.com",
"affectedData": [
{
"vendor": "n/a",
"product": "https://github.com/concrete5/concrete5",
"versions": [
{
"status": "affected",
"version": "Affected version Concrete CMS (concrete5) 8.5.6 and below. Fixed in Concrete CMS version 8.5.7 and 9.0.0"
}
]
}
]
}
],
"published": "2021-11-19T19:15:08.507",
"references": [
{
"url": "https://documentation.concretecms.org/developers/introduction/version-history/857-release-notes",
"tags": [
"Release Notes",
"Vendor Advisory"
],
"source": "support@hackerone.com"
},
{
"url": "https://hackerone.com/reports/1369312",
"tags": [
"Permissions Required"
],
"source": "support@hackerone.com"
},
{
"url": "https://documentation.concretecms.org/developers/introduction/version-history/857-release-notes",
"tags": [
"Release Notes",
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://hackerone.com/reports/1369312",
"tags": [
"Permissions Required"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Secondary",
"source": "support@hackerone.com",
"description": [
{
"lang": "en",
"value": "CWE-918"
}
]
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-918"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Concrete CMS (formerly concrete5) versions below 8.5.7 has a SSRF mitigation bypass using DNS Rebind attack giving an attacker the ability to fetch cloud IAAS (ex AWS) IAM keys.To fix this Concrete CMS no longer allows downloads from the local network and specifies the validated IP when downloading rather than relying on DNS.Discoverer: Adrian Tiron from FORTBRIDGE ( https://www.fortbridge.co.uk/ )The Concrete CMS team gave this a CVSS 3.1 score of 3.5 AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N . Please note that Cloud IAAS provider mis-configurations are not Concrete CMS vulnerabilities. A mitigation for this vulnerability is to make sure that the IMDS configurations are according to a cloud provider's best practices.This fix is also in Concrete version 9.0.0"
},
{
"lang": "es",
"value": "Concrete CMS (antes concrete5) versiones anteriores a 8.5.7, presentan una omisión de mitigación de tipo SSRF usando un ataque DNS Rebind dando a un atacante la capacidad de conseguir claves IAM en la nube IAAS (ex AWS). Para corregir esto Concrete CMS ya no permite descargas desde la red local y especifica la IP comprobada cuando descarga en lugar de confiar en DNS.Discoverer: Adrian Tiron de FORTBRIDGE ( https://www.fortbridge.co.uk/ ).El equipo de Concrete CMS dio a esto una puntuación CVSS 3.1 de 3.5 AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N . Por favor, tenga en cuenta que los errores de configuración de los proveedores de Cloud IAAS no son vulnerabilidades concretas de CMS. Una mitigación para esta vulnerabilidad es asegurarse de que las configuraciones de IMDS están de acuerdo con las mejores prácticas del proveedor de la nube. Esta corrección también está en Concrete versión 9.0.0"
}
],
"lastModified": "2026-06-17T03:38:07.730",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "2B7FD65C-EFA6-40A6-9698-FFEDD4846EE1",
"versionEndExcluding": "8.5.7"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "support@hackerone.com"
}