UBUNTU-CVE-2021-20233

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    UBUNTU-CVE-2021-20233

    Published: 2 Mar 2021Last Modified: 4 Feb 2026
    Upstream:
    CVE-2021-20233
    Aliases:
    USN-4992-1

    Summary:

    Details: A flaw was found in grub2 in versions prior to 2.06. Setparam_prefix() in the menu rendering code performs a length calculation on the assumption that expressing a quoted single quote will require 3 characters, while it actually requires 4 characters which allows an attacker to corrupt memory by one byte for each quote in the input. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

    References: https://ubuntu.com/security/CVE-2021-20233, https://ubuntu.com/security/notices/USN-4992-1, https://www.cve.org/CVERecord?id=CVE-2021-20233

    Affected packages

    Package

    Name: grub2-signed

    Purl: pkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra-legacy/trusty

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -None

    Affected versions

    1.22

    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
    UBUNTU-CVE-2021-20233 | CVE-DB