msrc_cve-2021-4034
Vulnerability from csaf_microsoft
Published
2022-01-02 00:00
Modified
2022-01-30 08:00
Summary
A local privilege escalation vulnerability was found on polkit's pkexec utility. The pkexec application is a setuid tool designed to allow unprivileged users to run commands as privileged users according predefined policies. The current version of pkexec doesn't handle the calling parameters count correctly and ends trying to execute environment variables as commands. An attacker can leverage this by crafting environment variables in such a way it'll induce pkexec to execute arbitrary code. When successfully executed the attack can cause a local privilege escalation given unprivileged users administrative rights on the target machine.

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/"
      }
    },
    "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-2021-4034 A local privilege escalation vulnerability was found on polkit\u0027s pkexec utility. The pkexec application is a setuid tool designed to allow unprivileged users to run commands as privileged users according predefined policies. The current version of pkexec doesn\u0027t handle the calling parameters count correctly and ends trying to execute environment variables as commands. An attacker can leverage this by crafting environment variables in such a way it\u0027ll induce pkexec to execute arbitrary code. When successfully executed the attack can cause a local privilege escalation given unprivileged users administrative rights on the target machine. - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2022/msrc_cve-2021-4034.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 local privilege escalation vulnerability was found on polkit\u0027s pkexec utility. The pkexec application is a setuid tool designed to allow unprivileged users to run commands as privileged users according predefined policies. The current version of pkexec doesn\u0027t handle the calling parameters count correctly and ends trying to execute environment variables as commands. An attacker can leverage this by crafting environment variables in such a way it\u0027ll induce pkexec to execute arbitrary code. When successfully executed the attack can cause a local privilege escalation given unprivileged users administrative rights on the target machine.",
    "tracking": {
      "current_release_date": "2022-01-30T08:00:00.000Z",
      "generator": {
        "date": "2025-10-19T23:13:23.055Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2021-4034",
      "initial_release_date": "2022-01-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2022-01-30T08:00:00.000Z",
          "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_version",
                "name": "2.0",
                "product": {
                  "name": "CBL Mariner 2.0",
                  "product_id": "17086"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003ccm1 polkit 0.116-6",
                "product": {
                  "name": "\u003ccm1 polkit 0.116-6",
                  "product_id": "2"
                }
              },
              {
                "category": "product_version",
                "name": "cm1 polkit 0.116-6",
                "product": {
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              },
              {
                "category": "product_version_range",
                "name": "\u003ccbl2 polkit 0.119-2",
                "product": {
                  "name": "\u003ccbl2 polkit 0.119-2",
                  "product_id": "1"
                }
              },
              {
                "category": "product_version",
                "name": "cbl2 polkit 0.119-2",
                "product": {
                  "name": "cbl2 polkit 0.119-2",
                  "product_id": "18906"
                }
              }
            ],
            "category": "product_name",
            "name": "polkit"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003ccm1 polkit 0.116-6 as a component of CBL Mariner 1.0",
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        "relates_to_product_reference": "16820"
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        "relates_to_product_reference": "16820"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
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        "relates_to_product_reference": "17086"
      },
      {
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        },
        "product_reference": "18906",
        "relates_to_product_reference": "17086"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2021-4034",
      "cwe": {
        "id": "CWE-125",
        "name": "Out-of-bounds Read"
      },
      "notes": [
        {
          "category": "general",
          "text": "redhat",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "fixed": [
          "18898-16820",
          "18906-17086"
        ],
        "known_affected": [
          "16820-2",
          "17086-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2021-4034 A local privilege escalation vulnerability was found on polkit\u0027s pkexec utility. The pkexec application is a setuid tool designed to allow unprivileged users to run commands as privileged users according predefined policies. The current version of pkexec doesn\u0027t handle the calling parameters count correctly and ends trying to execute environment variables as commands. An attacker can leverage this by crafting environment variables in such a way it\u0027ll induce pkexec to execute arbitrary code. When successfully executed the attack can cause a local privilege escalation given unprivileged users administrative rights on the target machine. - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2022/msrc_cve-2021-4034.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2022-01-30T08:00:00.000Z",
          "details": "0.116-6:Security Update:https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade",
          "product_ids": [
            "16820-2"
          ],
          "url": "https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade"
        },
        {
          "category": "vendor_fix",
          "date": "2022-01-30T08:00:00.000Z",
          "details": "0.119-2:Security Update:https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade",
          "product_ids": [
            "17086-1"
          ],
          "url": "https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "environmentalsScore": 0.0,
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "temporalScore": 7.8,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "products": [
            "16820-2",
            "17086-1"
          ]
        }
      ],
      "title": "A local privilege escalation vulnerability was found on polkit\u0027s pkexec utility. The pkexec application is a setuid tool designed to allow unprivileged users to run commands as privileged users according predefined policies. The current version of pkexec doesn\u0027t handle the calling parameters count correctly and ends trying to execute environment variables as commands. An attacker can leverage this by crafting environment variables in such a way it\u0027ll induce pkexec to execute arbitrary code. When successfully executed the attack can cause a local privilege escalation given unprivileged users administrative rights on the target machine."
    }
  ]
}


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