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CVE-2021-42286

Status: ModifiedHigh (7.8)—

Windows Core Shell SI Host Extension Framework for Composable Shell Elevation of Privilege Vulnerability

CVSS

Exploitation probability (EPSS)

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 (3)

Microsoft — Windows 10Microsoft — Windows ServerMicrosoft — Windows Server 2016

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2021-42286",
  "cveTags": [],
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          "options": [
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              "exploitation": "none"
            },
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              "automatable": "no"
            },
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              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2024-01-05T21:27:42.688940Z"
        }
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          "vectorString": "AV:L/AC:L/Au:N/C:P/I:P/A:P",
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          "confidentialityImpact": "PARTIAL"
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        "acInsufInfo": false,
        "impactScore": 6.4,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 3.9,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
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          "integrityImpact": "HIGH",
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          "platforms": [
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        {
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              "version": "10.0.0",
              "lessThan": "10.0.19041.1348",
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          ],
          "platforms": [
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          ]
        },
        {
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          "product": "Windows Server version 20H2",
          "versions": [
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              "version": "10.0.0",
              "lessThan": "10.0.19041.1348",
              "versionType": "custom"
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          ],
          "platforms": [
            "x64-based Systems"
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  ],
  "published": "2021-11-10T01:19:45.897",
  "references": [
    {
      "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-42286",
      "source": "secure@microsoft.com"
    },
    {
      "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42286",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-269"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Windows Core Shell SI Host Extension Framework for Composable Shell Elevation of Privilege Vulnerability"
    },
    {
      "lang": "es",
      "value": "Una vulnerabilidad de Elevación de Privilegios en el Marco de Extensión del Host de Windows Core Shell SI para Composable Shell"
    }
  ],
  "lastModified": "2026-08-19T17:18:00.417",
  "configurations": [
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  "sourceIdentifier": "secure@microsoft.com"
}