MSRC_CVE-2020-10711

Vulnerability from csaf_microsoft - Published: 2020-05-02 00:00 - Updated: 2020-09-25 00:00
Summary
A NULL pointer dereference flaw was found in the Linux kernel's SELinux subsystem in versions before 5.7. This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine it sets the security attribute to indicate that the category bitmap is present even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel resulting in a denial of service.

Notes

Additional Resources
To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle
Disclaimer
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.
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{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
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    "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-2020-10711 A NULL pointer dereference flaw was found in the Linux kernel\u0027s SELinux subsystem in versions before 5.7. This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol\u0027s category bitmap into the SELinux extensible bitmap via the\u0027 ebitmap_netlbl_import\u0027 routine. While processing the CIPSO restricted bitmap tag in the \u0027cipso_v4_parsetag_rbm\u0027 routine it sets the security attribute to indicate that the category bitmap is present even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel resulting in a denial of service. - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2020/msrc_cve-2020-10711.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 the Linux kernel\u0027s SELinux subsystem in versions before 5.7. This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol\u0027s category bitmap into the SELinux extensible bitmap via the\u0027 ebitmap_netlbl_import\u0027 routine. While processing the CIPSO restricted bitmap tag in the \u0027cipso_v4_parsetag_rbm\u0027 routine it sets the security attribute to indicate that the category bitmap is present even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel resulting in a denial of service.",
    "tracking": {
      "current_release_date": "2020-09-25T00:00:00.000Z",
      "generator": {
        "date": "2025-10-19T17:53:44.591Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2020-10711",
      "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",
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                }
              }
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          {
            "branches": [
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                "category": "product_version_range",
                "name": "\u003ccm1 kernel 5.4.91-3",
                "product": {
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                  "product_id": "1"
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              },
              {
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                "name": "cm1 kernel 5.4.91-3",
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    "relationships": [
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        "category": "default_component_of",
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          "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-2020-10711",
      "cwe": {
        "id": "CWE-476",
        "name": "NULL Pointer Dereference"
      },
      "notes": [
        {
          "category": "general",
          "text": "redhat",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "fixed": [
          "17036-16820"
        ],
        "known_affected": [
          "16820-1"
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      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2020-10711 A NULL pointer dereference flaw was found in the Linux kernel\u0027s SELinux subsystem in versions before 5.7. This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol\u0027s category bitmap into the SELinux extensible bitmap via the\u0027 ebitmap_netlbl_import\u0027 routine. While processing the CIPSO restricted bitmap tag in the \u0027cipso_v4_parsetag_rbm\u0027 routine it sets the security attribute to indicate that the category bitmap is present even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel resulting in a denial of service. - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2020/msrc_cve-2020-10711.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": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "environmentalsScore": 0.0,
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "temporalScore": 5.9,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/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 the Linux kernel\u0027s SELinux subsystem in versions before 5.7. This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol\u0027s category bitmap into the SELinux extensible bitmap via the\u0027 ebitmap_netlbl_import\u0027 routine. While processing the CIPSO restricted bitmap tag in the \u0027cipso_v4_parsetag_rbm\u0027 routine it sets the security attribute to indicate that the category bitmap is present even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel resulting in a denial of service."
    }
  ]
}


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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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