{"affected": [{"affectedData": [{"cpes": ["cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_9:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Microsoft Exchange Server 2019 Cumulative Update 9", "vendor": "Microsoft", "versions": [{"lessThan": "15.02.0858.012", "status": "affected", "version": "15.02.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_20:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Microsoft Exchange Server 2016 Cumulative Update 20", "vendor": "Microsoft", "versions": [{"lessThan": "15.01.2242.010", "status": "affected", "version": "15.01.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Microsoft Exchange Server 2013 Cumulative Update 23", "vendor": "Microsoft", "versions": [{"lessThan": "15.00.1497.018", "status": "affected", "version": "15.00.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_19:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Microsoft Exchange Server 2016 Cumulative Update 19", "vendor": "Microsoft", "versions": [{"lessThan": "15.01.2176.014", "status": "affected", "version": "15.01.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_8:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Microsoft Exchange Server 2019 Cumulative Update 8", "vendor": "Microsoft", "versions": [{"lessThan": "15.02.0792.015", "status": "affected", "version": "15.02.0", "versionType": "custom"}]}], "source": "secure@microsoft.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:*", "matchCriteriaId": "DA166F2A-D83B-4D50-AD0B-668D813E0585", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_19:*:*:*:*:*:*", "matchCriteriaId": "28FCA0E8-7D27-4746-9731-91B834CA3E64", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_20:*:*:*:*:*:*", "matchCriteriaId": "19C1EE0C-B8DD-4B91-BE4B-1C42D72FB718", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_8:*:*:*:*:*:*", "matchCriteriaId": "44ECF39A-1DE1-4870-A494-06A53494338D", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_9:*:*:*:*:*:*", "matchCriteriaId": "71CDF29B-116B-4DE2-AFD0-B62477FF0AEB", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Microsoft Exchange Server Spoofing Vulnerability"}, {"lang": "es", "value": "Una vulnerabilidad de Suplantaci\u00f3n de Identidad de Microsoft Exchange Server"}], "id": "CVE-2021-31209", "lastModified": "2026-06-17T03:51:27.370", "metrics": {"cvssMetricV2": [{"acInsufInfo": false, "baseSeverity": "MEDIUM", "cvssData": {"accessComplexity": "MEDIUM", "accessVector": "NETWORK", "authentication": "NONE", "availabilityImpact": "NONE", "baseScore": 5.8, "confidentialityImpact": "PARTIAL", "integrityImpact": "PARTIAL", "vectorString": "AV:N/AC:M/Au:N/C:P/I:P/A:N", "version": "2.0"}, "exploitabilityScore": 8.6, "impactScore": 4.9, "obtainAllPrivilege": false, "obtainOtherPrivilege": false, "obtainUserPrivilege": false, "source": "nvd@nist.gov", "type": "Primary", "userInteractionRequired": true}], "cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 4.2, "source": "secure@microsoft.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 5.2, "source": "nvd@nist.gov", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2021-31209", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2025-02-28T19:25:48.678953Z", "version": "2.0.3"}}]}, "published": "2021-05-11T19:15:10.467", "references": [{"source": "secure@microsoft.com", "tags": ["Patch", "Vendor Advisory"], "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31209"}, {"source": "secure@microsoft.com", "tags": ["Third Party Advisory", "VDB Entry"], "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-615/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch", "Vendor Advisory"], "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31209"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Third Party Advisory", "VDB Entry"], "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-615/"}], "sourceIdentifier": "secure@microsoft.com", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-290"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}