{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "HAO LI of VenusTech ADLab"
        ]
      }
    ],
    "aggregate_severity": {
      "namespace": "https://www.microsoft.com/en-us/msrc/security-update-severity-rating-system",
      "text": "Important"
    },
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      },
      {
        "category": "general",
        "text": "Required. The vulnerability documented by this CVE requires customer action to resolve.",
        "title": "Customer Action"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2021-38644 Microsoft MPEG-2 Video Extension Remote Code Execution Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-38644"
      },
      {
        "category": "self",
        "summary": "CVE-2021-38644 Microsoft MPEG-2 Video Extension Remote Code Execution Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2021/msrc_cve-2021-38644.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Exploitability Index",
        "url": "https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "Microsoft MPEG-2 Video Extension Remote Code Execution Vulnerability",
    "tracking": {
      "current_release_date": "2021-09-14T07:00:00.000Z",
      "generator": {
        "date": "2026-08-10T15:10:32.793Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2021-38644",
      "initial_release_date": "2021-09-14T07:00:00.000Z",
      "revision_history": [
        {
          "date": "2021-09-14T07:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2021-38644",
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "No. Only customers who have installed this app from the Microsoft Store may be vulnerable.\nThe Microsoft Store will automatically update affected customers. Alternatively, customers can get the update immediately; see here for details.\nIt is possible for customers to disable automatic updates for the Microsoft Store. The Microsoft Store will not automatically install this update for those customers.\nCustomers using the Microsoft Store for Business and Microsoft Store for Education can get this update through their organizations.\nApp package versions 1.0.42152.0 and later contain this update.\nYou can check the package version in PowerShell:\nGet-AppxPackage -Name Microsoft.MPEG2VideoExtension",
          "title": "Is Windows vulnerable in the default configuration?"
        }
      ],
      "product_status": {
        "fixed": [
          "11936"
        ],
        "known_affected": [
          "1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2021-38644 Microsoft MPEG-2 Video Extension Remote Code Execution Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-38644"
        },
        {
          "category": "self",
          "summary": "CVE-2021-38644 Microsoft MPEG-2 Video Extension Remote Code Execution Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2021/msrc_cve-2021-38644.json"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "environmentalScore": 0.0,
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "UNCHANGED",
            "temporalScore": 6.8,
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "1"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Remote Code Execution"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely;Older Software Release:Exploitation Less Likely"
        }
      ],
      "title": "Microsoft MPEG-2 Video Extension Remote Code Execution Vulnerability"
    }
  ]
}