{
  "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-2021-4209 A NULL pointer dereference flaw was found in GnuTLS. As Nettle\u0027s hash update functions internally call memcpy providing zero-length input may cause undefined behavior. This flaw leads to a denial of service after authentication in rare circumstances. - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2022/msrc_cve-2021-4209.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 NULL pointer dereference flaw was found in GnuTLS. As Nettle\u0027s hash update functions internally call memcpy providing zero-length input may cause undefined behavior. This flaw leads to a denial of service after authentication in rare circumstances.",
    "tracking": {
      "current_release_date": "2022-08-31T00:00:00.000Z",
      "generator": {
        "date": "2025-10-19T23:51:07.216Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2021-4209",
      "initial_release_date": "2022-08-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2022-08-31T00:00:00.000Z",
          "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 gnutls 3.6.14-7",
                "product": {
                  "name": "\u003ccm1 gnutls 3.6.14-7",
                  "product_id": "1"
                }
              },
              {
                "category": "product_version",
                "name": "cm1 gnutls 3.6.14-7",
                "product": {
                  "name": "cm1 gnutls 3.6.14-7",
                  "product_id": "18862"
                }
              }
            ],
            "category": "product_name",
            "name": "gnutls"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003ccm1 gnutls 3.6.14-7 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 gnutls 3.6.14-7 as a component of CBL Mariner 1.0",
          "product_id": "18862-16820"
        },
        "product_reference": "18862",
        "relates_to_product_reference": "16820"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2021-4209",
      "cwe": {
        "id": "CWE-476",
        "name": "NULL Pointer Dereference"
      },
      "notes": [
        {
          "category": "general",
          "text": "redhat",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "fixed": [
          "18862-16820"
        ],
        "known_affected": [
          "16820-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2021-4209 A NULL pointer dereference flaw was found in GnuTLS. As Nettle\u0027s hash update functions internally call memcpy providing zero-length input may cause undefined behavior. This flaw leads to a denial of service after authentication in rare circumstances. - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2022/msrc_cve-2021-4209.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2022-08-31T00:00:00.000Z",
          "details": "3.6.14-7: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": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "environmentalsScore": 0.0,
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "temporalScore": 6.5,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "products": [
            "16820-1"
          ]
        }
      ],
      "title": "A NULL pointer dereference flaw was found in GnuTLS. As Nettle\u0027s hash update functions internally call memcpy providing zero-length input may cause undefined behavior. This flaw leads to a denial of service after authentication in rare circumstances."
    }
  ]
}