{
  "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-2019-20794 An issue was discovered in the Linux kernel 4.18 through 5.6.11 when unprivileged user namespaces are allowed. A user can create their own PID namespace and mount a FUSE filesystem. Upon interaction with this FUSE filesystem if the userspace component is terminated via a kill of the PID namespace\u0027s pid 1 it will result in a hung task and resources being permanently locked up until system reboot. This can result in resource exhaustion. - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2020/msrc_cve-2019-20794.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": "An issue was discovered in the Linux kernel 4.18 through 5.6.11 when unprivileged user namespaces are allowed. A user can create their own PID namespace and mount a FUSE filesystem. Upon interaction with this FUSE filesystem if the userspace component is terminated via a kill of the PID namespace\u0027s pid 1 it will result in a hung task and resources being permanently locked up until system reboot. This can result in resource exhaustion.",
    "tracking": {
      "current_release_date": "2020-09-25T00:00:00.000Z",
      "generator": {
        "date": "2025-10-19T17:53:44.608Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2019-20794",
      "initial_release_date": "2020-05-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2020-09-25T00:00:00.000Z",
          "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 kernel 5.4.91-3",
                "product": {
                  "name": "\u003ccm1 kernel 5.4.91-3",
                  "product_id": "1"
                }
              },
              {
                "category": "product_version",
                "name": "cm1 kernel 5.4.91-3",
                "product": {
                  "name": "cm1 kernel 5.4.91-3",
                  "product_id": "17036"
                }
              }
            ],
            "category": "product_name",
            "name": "kernel"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003ccm1 kernel 5.4.91-3 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 kernel 5.4.91-3 as a component of CBL Mariner 1.0",
          "product_id": "17036-16820"
        },
        "product_reference": "17036",
        "relates_to_product_reference": "16820"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2019-20794",
      "cwe": {
        "id": "CWE-772",
        "name": "Missing Release of Resource after Effective Lifetime"
      },
      "notes": [
        {
          "category": "general",
          "text": "mitre",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "fixed": [
          "17036-16820"
        ],
        "known_affected": [
          "16820-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2019-20794 An issue was discovered in the Linux kernel 4.18 through 5.6.11 when unprivileged user namespaces are allowed. A user can create their own PID namespace and mount a FUSE filesystem. Upon interaction with this FUSE filesystem if the userspace component is terminated via a kill of the PID namespace\u0027s pid 1 it will result in a hung task and resources being permanently locked up until system reboot. This can result in resource exhaustion. - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2020/msrc_cve-2019-20794.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2020-09-25T00:00:00.000Z",
          "details": "5.4.91-3: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": "HIGH",
            "baseScore": 4.7,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "environmentalsScore": 0.0,
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "temporalScore": 4.7,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "products": [
            "16820-1"
          ]
        }
      ],
      "title": "An issue was discovered in the Linux kernel 4.18 through 5.6.11 when unprivileged user namespaces are allowed. A user can create their own PID namespace and mount a FUSE filesystem. Upon interaction with this FUSE filesystem if the userspace component is terminated via a kill of the PID namespace\u0027s pid 1 it will result in a hung task and resources being permanently locked up until system reboot. This can result in resource exhaustion."
    }
  ]
}