UBUNTU-CVE-2020-27749

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    UBUNTU-CVE-2020-27749

    Published: 2 Mar 2021Last Modified: 4 Feb 2026
    Upstream:
    CVE-2020-27749
    Aliases:
    USN-4992-1

    Summary:

    Details: A flaw was found in grub2 in versions prior to 2.06. Variable names present are expanded in the supplied command line into their corresponding variable contents, using a 1kB stack buffer for temporary storage, without sufficient bounds checking. If the function is called with a command line that references a variable with a sufficiently large payload, it is possible to overflow the stack buffer, corrupt the stack frame and control execution which could also circumvent Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

    References: https://ubuntu.com/security/CVE-2020-27749, https://ubuntu.com/security/notices/USN-4992-1, https://www.cve.org/CVERecord?id=CVE-2020-27749

    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-2020-27749 | CVE-DB