UBUNTU-CVE-2018-20482

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    UBUNTU-CVE-2018-20482

    Published: 26 Dec 2018Last Modified: 4 Feb 2026
    Upstream:
    CVE-2018-20482
    Aliases:
    USN-4692-1

    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).

    References: https://ubuntu.com/security/CVE-2018-20482, https://utcc.utoronto.ca/~cks/space/blog/sysadmin/TarFindingTruncateBug, https://news.ycombinator.com/item?id=18745431, https://twitter.com/thatcks/status/1076166645708668928, http://lists.gnu.org/archive/html/bug-tar/2018-12/msg00023.html, https://ubuntu.com/security/notices/USN-4692-1, https://www.cve.org/CVERecord?id=CVE-2018-20482

    Affected packages

    Package

    Name: tar

    Purl: pkg:deb/ubuntu/[email protected]+esm1?arch=source&distro=trusty/esm

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -1.27.1-1ubuntu0.1+esm1

    Affected versions

    1.26+dfsg-8

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High