{
  "document": {
    "category": "csaf_vex",
    "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"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2021-3631 A flaw was found in libvirt while it generates SELinux MCS category pairs for VMs\u0027 dynamic labels. This flaw allows one exploited guest to access files labeled for another guest resulting in the breaking out of sVirt confinement. The highest threat from this vulnerability is to confidentiality and integrity. - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2022/msrc_cve-2021-3631.json"
      },
      {
        "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": "A flaw was found in libvirt while it generates SELinux MCS category pairs for VMs\u0027 dynamic labels. This flaw allows one exploited guest to access files labeled for another guest resulting in the breaking out of sVirt confinement. The highest threat from this vulnerability is to confidentiality and integrity.",
    "tracking": {
      "current_release_date": "2022-03-11T00:00:00.000Z",
      "generator": {
        "date": "2025-10-19T23:23:33.140Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2021-3631",
      "initial_release_date": "2022-03-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2022-03-11T00:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "1.0",
                "product": {
                  "name": "CBL Mariner 1.0",
                  "product_id": "16820"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003ccm1 libvirt 6.1.0-5",
                "product": {
                  "name": "\u003ccm1 libvirt 6.1.0-5",
                  "product_id": "1"
                }
              },
              {
                "category": "product_version",
                "name": "cm1 libvirt 6.1.0-5",
                "product": {
                  "name": "cm1 libvirt 6.1.0-5",
                  "product_id": "18897"
                }
              }
            ],
            "category": "product_name",
            "name": "libvirt"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003ccm1 libvirt 6.1.0-5 as a component of CBL Mariner 1.0",
          "product_id": "16820-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "16820"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "cm1 libvirt 6.1.0-5 as a component of CBL Mariner 1.0",
          "product_id": "18897-16820"
        },
        "product_reference": "18897",
        "relates_to_product_reference": "16820"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2021-3631",
      "cwe": {
        "id": "CWE-732",
        "name": "Incorrect Permission Assignment for Critical Resource"
      },
      "notes": [
        {
          "category": "general",
          "text": "redhat",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "fixed": [
          "18897-16820"
        ],
        "known_affected": [
          "16820-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2021-3631 A flaw was found in libvirt while it generates SELinux MCS category pairs for VMs\u0027 dynamic labels. This flaw allows one exploited guest to access files labeled for another guest resulting in the breaking out of sVirt confinement. The highest threat from this vulnerability is to confidentiality and integrity. - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2022/msrc_cve-2021-3631.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2022-03-11T00:00:00.000Z",
          "details": "6.1.0-5:Security Update:https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade",
          "product_ids": [
            "16820-1"
          ],
          "url": "https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "HIGH",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "environmentalsScore": 0.0,
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "temporalScore": 6.3,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          },
          "products": [
            "16820-1"
          ]
        }
      ],
      "title": "A flaw was found in libvirt while it generates SELinux MCS category pairs for VMs\u0027 dynamic labels. This flaw allows one exploited guest to access files labeled for another guest resulting in the breaking out of sVirt confinement. The highest threat from this vulnerability is to confidentiality and integrity."
    }
  ]
}