CVE-2021-31172
Status: ModifiedHigh (7.1)—
Microsoft SharePoint Server Spoofing Vulnerability
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
- Base score: 7.1
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 1.81%
- Percentile among all scored CVEs: 78
- Score date: 10/6/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (2)
CWEs
- NVD-CWE-noinfo
- CWE-290
References
Raw JSON (NVD)
Show
{
"id": "CVE-2021-31172",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2021-31172",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2025-02-28T19:25:52.601324Z"
}
}
],
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 5.8,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:M/Au:N/C:P/I:P/A:N",
"authentication": "NONE",
"integrityImpact": "PARTIAL",
"accessComplexity": "MEDIUM",
"availabilityImpact": "NONE",
"confidentialityImpact": "PARTIAL"
},
"acInsufInfo": false,
"impactScore": 4.9,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 8.6,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": true
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "secure@microsoft.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.1,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 4.2,
"exploitabilityScore": 2.8
},
{
"type": "Secondary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.1,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 4.2,
"exploitabilityScore": 2.8
}
]
},
"affected": [
{
"source": "secure@microsoft.com",
"affectedData": [
{
"cpes": [
"cpe:2.3:a:microsoft:sharepoint_server:2016:*:*:*:enterprise:*:*:*"
],
"vendor": "Microsoft",
"product": "Microsoft SharePoint Enterprise Server 2016",
"versions": [
{
"status": "affected",
"version": "16.0.0",
"lessThan": "16.0.5161.1000",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"cpes": [
"cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:*"
],
"vendor": "Microsoft",
"product": "Microsoft SharePoint Server 2019",
"versions": [
{
"status": "affected",
"version": "16.0.0",
"lessThan": "16.0.10374.20000",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"cpes": [
"cpe:2.3:a:microsoft:sharepoint_foundation:2013:sp1:*:*:*:*:*:*"
],
"vendor": "Microsoft",
"product": "Microsoft SharePoint Foundation 2013 Service Pack 1",
"versions": [
{
"status": "affected",
"version": "15.0.0",
"lessThan": "15.0.5345.1000",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
}
]
}
],
"published": "2021-05-11T19:15:09.527",
"references": [
{
"url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31172",
"tags": [
"Patch",
"Vendor Advisory"
],
"source": "secure@microsoft.com"
},
{
"url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31172",
"tags": [
"Patch",
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
]
},
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"description": [
{
"lang": "en",
"value": "CWE-290"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Microsoft SharePoint Server Spoofing Vulnerability"
},
{
"lang": "es",
"value": "Una vulnerabilidad de Suplantación de Identidad de Microsoft SharePoint. Este ID de CVE es diferente de CVE-2021-26418, CVE-2021-28478"
}
],
"lastModified": "2026-06-17T03:51:22.740",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:microsoft:sharepoint_foundation:2013:sp1:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "F71184B1-7461-4A05-A5D2-03D9EDDC30D5"
},
{
"criteria": "cpe:2.3:a:microsoft:sharepoint_server:2016:*:*:*:enterprise:*:*:*",
"vulnerable": true,
"matchCriteriaId": "F815EF1D-7B60-47BE-9AC2-2548F99F10E4"
},
{
"criteria": "cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "6122D014-5BF1-4AF4-8B4D-80205ED7785E"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "secure@microsoft.com"
}