{"id":"UBUNTU-CVE-2018-20482","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).","modified":"2026-02-04T02:49:12.179112Z","published":"2018-12-26T18:29:00Z","related":["USN-4692-1"],"upstream":["CVE-2018-20482"],"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"}],"affected":[{"package":{"name":"tar","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/tar@1.27.1-1ubuntu0.1+esm1?arch=source&distro=trusty/esm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.27.1-1ubuntu0.1+esm1"}]}],"versions":["1.26+dfsg-8","1.27-3","1.27-4","1.27.1-1","1.27.1-1ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.27.1-1ubuntu0.1+esm1","binary_name":"tar"},{"binary_version":"1.27.1-1ubuntu0.1+esm1","binary_name":"tar-scripts"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-20482.json"}},{"package":{"name":"tar","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/tar@1.28-2.1ubuntu0.2?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.28-2.1ubuntu0.2"}]}],"versions":["1.27.1-2","1.28-2ubuntu1","1.28-2.1","1.28-2.1ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.28-2.1ubuntu0.2","binary_name":"tar"},{"binary_version":"1.28-2.1ubuntu0.2","binary_name":"tar-scripts"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-20482.json"}},{"package":{"name":"tar","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/tar@1.29b-2ubuntu0.2?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.29b-2ubuntu0.2"}]}],"versions":["1.29b-2","1.29b-2ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.29b-2ubuntu0.2","binary_name":"tar"},{"binary_version":"1.29b-2ubuntu0.2","binary_name":"tar-scripts"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-20482.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","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":"Ubuntu","score":"low"}]}