msrc_cve-2021-3981
Vulnerability from csaf_microsoft
Published
2022-03-02 00:00
Modified
2024-06-30 07:00
Summary
A flaw in grub2 was found where its configuration file known as grub.cfg is being created with the wrong permission set allowing non privileged users to read its content. This represents a low severity confidentiality issue as those users can eventually read any encrypted passwords present in grub.cfg. This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no version with the fix is currently released.

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.


To clipboard 

{
  "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-2021-3981 A flaw in grub2 was found where its configuration file known as grub.cfg is being created with the wrong permission set allowing non privileged users to read its content. This represents a low severity confidentiality issue as those users can eventually read any encrypted passwords present in grub.cfg. This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no version with the fix is currently released. - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2022/msrc_cve-2021-3981.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 in grub2 was found where its configuration file known as grub.cfg is being created with the wrong permission set allowing non privileged users to read its content. This represents a low severity confidentiality issue as those users can eventually read any encrypted passwords present in grub.cfg. This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no version with the fix is currently released.",
    "tracking": {
      "current_release_date": "2024-06-30T07:00:00.000Z",
      "generator": {
        "date": "2025-10-19T23:23:33.132Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2021-3981",
      "initial_release_date": "2022-03-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2022-03-15T00:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2024-06-30T07:00:00.000Z",
          "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_version",
                "name": "2.0",
                "product": {
                  "name": "CBL Mariner 2.0",
                  "product_id": "17086"
                }
              },
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003ccm1 grub2 2.06~rc1-8",
                "product": {
                  "name": "\u003ccm1 grub2 2.06~rc1-8",
                  "product_id": "3"
                }
              },
              {
                "category": "product_version",
                "name": "cm1 grub2 2.06~rc1-8",
                "product": {
                  "name": "cm1 grub2 2.06~rc1-8",
                  "product_id": "18893"
                }
              },
              {
                "category": "product_version_range",
                "name": "\u003ccbl2 grub2 2.06-5",
                "product": {
                  "name": "\u003ccbl2 grub2 2.06-5",
                  "product_id": "2"
                }
              },
              {
                "category": "product_version",
                "name": "cbl2 grub2 2.06-5",
                "product": {
                  "name": "cbl2 grub2 2.06-5",
                  "product_id": "18894"
                }
              },
              {
                "category": "product_version_range",
                "name": "\u003cazl3 grub2 2.06-14",
                "product": {
                  "name": "\u003cazl3 grub2 2.06-14",
                  "product_id": "4"
                }
              },
              {
                "category": "product_version",
                "name": "azl3 grub2 2.06-14",
                "product": {
                  "name": "azl3 grub2 2.06-14",
                  "product_id": "18842"
                }
              },
              {
                "category": "product_version_range",
                "name": "\u003cazl3 grub2 2.06-23",
                "product": {
                  "name": "\u003cazl3 grub2 2.06-23",
                  "product_id": "1"
                }
              },
              {
                "category": "product_version",
                "name": "azl3 grub2 2.06-23",
                "product": {
                  "name": "azl3 grub2 2.06-23",
                  "product_id": "19663"
                }
              }
            ],
            "category": "product_name",
            "name": "grub2"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003ccm1 grub2 2.06~rc1-8 as a component of CBL Mariner 1.0",
          "product_id": "16820-3"
        },
        "product_reference": "3",
        "relates_to_product_reference": "16820"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "cm1 grub2 2.06~rc1-8 as a component of CBL Mariner 1.0",
          "product_id": "18893-16820"
        },
        "product_reference": "18893",
        "relates_to_product_reference": "16820"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003ccbl2 grub2 2.06-5 as a component of CBL Mariner 2.0",
          "product_id": "17086-2"
        },
        "product_reference": "2",
        "relates_to_product_reference": "17086"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "cbl2 grub2 2.06-5 as a component of CBL Mariner 2.0",
          "product_id": "18894-17086"
        },
        "product_reference": "18894",
        "relates_to_product_reference": "17086"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003cazl3 grub2 2.06-14 as a component of Azure Linux 3.0",
          "product_id": "17084-4"
        },
        "product_reference": "4",
        "relates_to_product_reference": "17084"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 grub2 2.06-14 as a component of Azure Linux 3.0",
          "product_id": "18842-17084"
        },
        "product_reference": "18842",
        "relates_to_product_reference": "17084"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003cazl3 grub2 2.06-23 as a component of Azure Linux 3.0",
          "product_id": "17084-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17084"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 grub2 2.06-23 as a component of Azure Linux 3.0",
          "product_id": "19663-17084"
        },
        "product_reference": "19663",
        "relates_to_product_reference": "17084"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2021-3981",
      "cwe": {
        "id": "CWE-276",
        "name": "Incorrect Default Permissions"
      },
      "notes": [
        {
          "category": "general",
          "text": "redhat",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "fixed": [
          "18893-16820",
          "18894-17086",
          "18842-17084",
          "19663-17084"
        ],
        "known_affected": [
          "16820-3",
          "17086-2",
          "17084-4",
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2021-3981 A flaw in grub2 was found where its configuration file known as grub.cfg is being created with the wrong permission set allowing non privileged users to read its content. This represents a low severity confidentiality issue as those users can eventually read any encrypted passwords present in grub.cfg. This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no version with the fix is currently released. - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2022/msrc_cve-2021-3981.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2022-03-15T00:00:00.000Z",
          "details": "-:Security Update:https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade",
          "product_ids": [
            "16820-3"
          ],
          "url": "https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade"
        },
        {
          "category": "vendor_fix",
          "date": "2022-03-15T00:00:00.000Z",
          "details": "2.06-5:Security Update:https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade",
          "product_ids": [
            "17086-2"
          ],
          "url": "https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade"
        },
        {
          "category": "vendor_fix",
          "date": "2022-03-15T00:00:00.000Z",
          "details": "2.06-14:Security Update:https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade",
          "product_ids": [
            "17084-4",
            "17084-1"
          ],
          "url": "https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 3.3,
            "baseSeverity": "LOW",
            "confidentialityImpact": "LOW",
            "environmentalsScore": 0.0,
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "temporalScore": 3.3,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          },
          "products": [
            "16820-3",
            "17086-2",
            "17084-4",
            "17084-1"
          ]
        }
      ],
      "title": "A flaw in grub2 was found where its configuration file known as grub.cfg is being created with the wrong permission set allowing non privileged users to read its content. This represents a low severity confidentiality issue as those users can eventually read any encrypted passwords present in grub.cfg. This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no version with the fix is currently released."
    }
  ]
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.