{
  "document": {
    "aggregate_severity": {
      "text": "High"
    },
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "TuxCare License Agreement",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.",
        "title": "Terms of Use"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "https://tuxcare.com/contact/",
      "name": "TuxCare",
      "namespace": "https://tuxcare.com/"
    },
    "references": [
      {
        "category": "self",
        "summary": "Canonical URL",
        "url": "https://security.tuxcare.com/csaf/v2/els_os/ubuntu16.04els/vex/2018/cve-2018-20834-els_os-ubuntu16_04els.json"
      }
    ],
    "tracking": {
      "current_release_date": "2026-04-24T11:49:52Z",
      "generator": {
        "date": "2026-04-24T11:49:52Z",
        "engine": {
          "name": "pyCSAF"
        }
      },
      "id": "CVE-2018-20834-ELS_OS-UBUNTU16.04ELS",
      "initial_release_date": "2018-01-01T00:00:00Z",
      "revision_history": [
        {
          "date": "2018-01-01T00:00:00Z",
          "number": "1",
          "summary": "Initial version"
        },
        {
          "date": "2026-04-20T15:27:24Z",
          "number": "2",
          "summary": "Official Publication"
        },
        {
          "date": "2026-04-24T11:49:52Z",
          "number": "3",
          "summary": "Update document"
        }
      ],
      "status": "final",
      "version": "3"
    },
    "title": "Security update on CVE-2018-20834"
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_name",
                "name": "Ubuntu 16.04",
                "product": {
                  "name": "Ubuntu 16.04",
                  "product_id": "Ubuntu-16",
                  "product_identification_helper": {
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            "category": "product_family",
            "name": "Ubuntu"
          }
        ],
        "category": "vendor",
        "name": "Canonical Ltd."
      },
      {
        "branches": [
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                "category": "product_version",
                "name": "tar-scripts-0:1.28-2.1ubuntu0.2+tuxcare.els2.amd64",
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                "product": {
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            "category": "architecture",
            "name": "amd64"
          }
        ],
        "category": "vendor",
        "name": "CloudLinux"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "tar-scripts-0:1.28-2.1ubuntu0.2+tuxcare.els2.amd64 as a component of Ubuntu 16.04",
          "product_id": "Ubuntu-16:tar-scripts-0:1.28-2.1ubuntu0.2+tuxcare.els2.amd64"
        },
        "product_reference": "tar-scripts-0:1.28-2.1ubuntu0.2+tuxcare.els2.amd64",
        "relates_to_product_reference": "Ubuntu-16"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "tar-scripts-0:1.28-2.1ubuntu0.2+tuxcare.els1.amd64 as a component of Ubuntu 16.04",
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        "relates_to_product_reference": "Ubuntu-16"
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        "relates_to_product_reference": "Ubuntu-16"
      }
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  },
  "vulnerabilities": [
    {
      "cve": "CVE-2018-20834",
      "cwe": {
        "id": "CWE-59",
        "name": "Improper Link Resolution Before File Access ('Link Following')"
      },
      "notes": [
        {
          "category": "description",
          "text": "A vulnerability was found in node-tar before version 4.4.2 (excluding version 2.2.2). An Arbitrary File Overwrite issue exists when extracting a tarball containing a hardlink to a file that already exists on the system, in conjunction with a later plain file with the same name as the hardlink. This plain file content replaces the existing file content. A patch has been applied to node-tar v2.2.2).",
          "title": "Vulnerability description"
        },
        {
          "category": "general",
          "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.",
          "title": "CVSS score applicability"
        },
        {
          "category": "other",
          "text": "TuxCare has assessed that this vulnerability does not impact any currently supported TuxCare products. This evaluation may change as new information becomes available. For additional details regarding this vulnerability and affected products, refer to the provided references.",
          "title": "Statement"
        }
      ],
      "product_status": {
        "known_not_affected": [
          "Ubuntu-16:tar-0:1.28-2.1ubuntu0.2+tuxcare.els2.amd64",
          "Ubuntu-16:tar-scripts-0:1.28-2.1ubuntu0.2+tuxcare.els1.amd64",
          "Ubuntu-16:tar-scripts-0:1.28-2.1ubuntu0.2+tuxcare.els2.amd64"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://cve.tuxcare.com/els/cve/CVE-2018-20834"
        },
        {
          "category": "external",
          "summary": "https://access.redhat.com/errata/RHSA-2019:1821",
          "url": "https://access.redhat.com/errata/RHSA-2019:1821"
        },
        {
          "category": "external",
          "summary": "https://github.com/npm/node-tar/commit/7ecef07da6a9e72cc0c4d0c9c6a8e85b6b52395d",
          "url": "https://github.com/npm/node-tar/commit/7ecef07da6a9e72cc0c4d0c9c6a8e85b6b52395d"
        },
        {
          "category": "external",
          "summary": "https://github.com/npm/node-tar/commit/b0c58433c22f5e7fe8b1c76373f27e3f81dcd4c8",
          "url": "https://github.com/npm/node-tar/commit/b0c58433c22f5e7fe8b1c76373f27e3f81dcd4c8"
        },
        {
          "category": "external",
          "summary": "https://github.com/npm/node-tar/commits/v2.2.2",
          "url": "https://github.com/npm/node-tar/commits/v2.2.2"
        },
        {
          "category": "external",
          "summary": "https://github.com/npm/node-tar/compare/58a8d43...a5f7779",
          "url": "https://github.com/npm/node-tar/compare/58a8d43...a5f7779"
        },
        {
          "category": "external",
          "summary": "https://hackerone.com/reports/344595",
          "url": "https://hackerone.com/reports/344595"
        },
        {
          "category": "external",
          "summary": "https://nvd.nist.gov/vuln/detail/CVE-2018-20834",
          "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-20834"
        }
      ],
      "release_date": "2019-04-30T19:29:00Z",
      "scores": [
        {
          "cvss_v2": {
            "accessComplexity": "LOW",
            "accessVector": "NETWORK",
            "authentication": "NONE",
            "availabilityImpact": "PARTIAL",
            "baseScore": 6.4,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "PARTIAL",
            "vectorString": "AV:N/AC:L/Au:N/C:N/I:P/A:P",
            "version": "2.0"
          },
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
            "version": "3.0"
          },
          "products": [
            "Ubuntu-16:tar-0:1.28-2.1ubuntu0.2+tuxcare.els2.amd64",
            "Ubuntu-16:tar-scripts-0:1.28-2.1ubuntu0.2+tuxcare.els1.amd64",
            "Ubuntu-16:tar-scripts-0:1.28-2.1ubuntu0.2+tuxcare.els2.amd64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Important"
        },
        {
          "category": "impact",
          "details": "important",
          "product_ids": [
            "Ubuntu-16:tar-0:1.28-2.1ubuntu0.2+tuxcare.els2.amd64",
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            "Ubuntu-16:tar-scripts-0:1.28-2.1ubuntu0.2+tuxcare.els2.amd64"
          ]
        }
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  ]
}