{
  "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-2021-3923 A flaw was found in the Linux kernel\u0027s implementation of RDMA over infiniband. An attacker with a privileged local account can leak kernel stack information when issuing commands to the /dev/infiniband/rdma_cm device node. While this access is unlikely to leak sensitive user information it can be further used to defeat existing kernel protection mechanisms. - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2023/msrc_cve-2021-3923.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 the Linux kernel\u0027s implementation of RDMA over infiniband. An attacker with a privileged local account can leak kernel stack information when issuing commands to the /dev/infiniband/rdma_cm device node. While this access is unlikely to leak sensitive user information it can be further used to defeat existing kernel protection mechanisms.",
    "tracking": {
      "current_release_date": "2023-05-03T00:00:00.000Z",
      "generator": {
        "date": "2025-10-20T00:21:27.850Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2021-3923",
      "initial_release_date": "2023-03-10T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2023-04-04T00:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2023-05-03T00:00:00.000Z",
          "legacy_version": "1.1",
          "number": "2",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "2"
    }
  },
  "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 5.10.177.1-1",
                "product": {
                  "name": "\u003ccm1 kernel 5.10.177.1-1",
                  "product_id": "1"
                }
              },
              {
                "category": "product_version",
                "name": "cm1 kernel 5.10.177.1-1",
                "product": {
                  "name": "cm1 kernel 5.10.177.1-1",
                  "product_id": "17902"
                }
              }
            ],
            "category": "product_name",
            "name": "kernel"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003ccm1 kernel 5.10.177.1-1 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 5.10.177.1-1 as a component of CBL Mariner 1.0",
          "product_id": "17902-16820"
        },
        "product_reference": "17902",
        "relates_to_product_reference": "16820"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2021-3923",
      "cwe": {
        "id": "CWE-200",
        "name": "Exposure of Sensitive Information to an Unauthorized Actor"
      },
      "notes": [
        {
          "category": "general",
          "text": "redhat",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "fixed": [
          "17902-16820"
        ],
        "known_affected": [
          "16820-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2021-3923 A flaw was found in the Linux kernel\u0027s implementation of RDMA over infiniband. An attacker with a privileged local account can leak kernel stack information when issuing commands to the /dev/infiniband/rdma_cm device node. While this access is unlikely to leak sensitive user information it can be further used to defeat existing kernel protection mechanisms. - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2023/msrc_cve-2021-3923.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2023-04-04T00:00:00.000Z",
          "details": "5.10.177.1-1: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": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 2.3,
            "baseSeverity": "LOW",
            "confidentialityImpact": "LOW",
            "environmentalsScore": 0.0,
            "integrityImpact": "NONE",
            "privilegesRequired": "HIGH",
            "scope": "UNCHANGED",
            "temporalScore": 2.3,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          },
          "products": [
            "16820-1"
          ]
        }
      ],
      "title": "A flaw was found in the Linux kernel\u0027s implementation of RDMA over infiniband. An attacker with a privileged local account can leak kernel stack information when issuing commands to the /dev/infiniband/rdma_cm device node. While this access is unlikely to leak sensitive user information it can be further used to defeat existing kernel protection mechanisms."
    }
  ]
}