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ubuntu-cve-2018-20482
Vulnerability from osv_ubuntu
Published
2018-12-26 18:29
Modified
2025-09-08 16:45
Summary
Details

GNU Tar through 1.30, when --sparse is used, mishandles file shrinkage during read access, which allows local users to cause a denial of service (infinite read loop in sparse_dump_region in sparse.c) by modifying a file that is supposed to be archived by a different user's process (e.g., a system backup running as root).

Severity
4.7 (Medium)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7 (Medium)
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
low
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "tar",
            "binary_version": "1.27.1-1ubuntu0.1+esm1"
          },
          {
            "binary_name": "tar-scripts",
            "binary_version": "1.27.1-1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "tar",
        "purl": "pkg:deb/ubuntu/tar@1.27.1-1ubuntu0.1+esm1?arch=source\u0026distro=trusty/esm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.27.1-1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.26+dfsg-8",
        "1.27-3",
        "1.27-4",
        "1.27.1-1",
        "1.27.1-1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "tar",
            "binary_version": "1.28-2.1ubuntu0.2"
          },
          {
            "binary_name": "tar-scripts",
            "binary_version": "1.28-2.1ubuntu0.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "tar",
        "purl": "pkg:deb/ubuntu/tar@1.28-2.1ubuntu0.2?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.28-2.1ubuntu0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.27.1-2",
        "1.28-2ubuntu1",
        "1.28-2.1",
        "1.28-2.1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "tar",
            "binary_version": "1.29b-2ubuntu0.2"
          },
          {
            "binary_name": "tar-scripts",
            "binary_version": "1.29b-2ubuntu0.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "tar",
        "purl": "pkg:deb/ubuntu/tar@1.29b-2ubuntu0.2?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.29b-2ubuntu0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.29b-2",
        "1.29b-2ubuntu0.1"
      ]
    }
  ],
  "aliases": [],
  "details": "GNU Tar through 1.30, when --sparse is used, mishandles file shrinkage during read access, which allows local users to cause a denial of service (infinite read loop in sparse_dump_region in sparse.c) by modifying a file that is supposed to be archived by a different user\u0027s process (e.g., a system backup running as root).",
  "id": "UBUNTU-CVE-2018-20482",
  "modified": "2025-09-08T16:45:06Z",
  "published": "2018-12-26T18:29:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2018-20482"
    },
    {
      "type": "REPORT",
      "url": "https://utcc.utoronto.ca/~cks/space/blog/sysadmin/TarFindingTruncateBug"
    },
    {
      "type": "REPORT",
      "url": "https://news.ycombinator.com/item?id=18745431"
    },
    {
      "type": "REPORT",
      "url": "https://twitter.com/thatcks/status/1076166645708668928"
    },
    {
      "type": "REPORT",
      "url": "http://lists.gnu.org/archive/html/bug-tar/2018-12/msg00023.html"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4692-1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2018-20482"
    }
  ],
  "related": [
    "USN-4692-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "low",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2018-20482"
  ]
}



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