UBUNTU-CVE-2021-4090

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    UBUNTU-CVE-2021-4090

    Published: 13 Dec 2021Last Modified: 4 Feb 2026
    Upstream:
    CVE-2021-4090

    Summary:

    Details: An out-of-bounds (OOB) memory write flaw was found in the NFSD in the Linux kernel. Missing sanity may lead to a write beyond bmval[bmlen-1] in nfsd4_decode_bitmap4 in fs/nfsd/nfs4xdr.c. In this flaw, a local attacker with user privilege may gain access to out-of-bounds memory, leading to a system integrity and confidentiality threat.

    References: https://ubuntu.com/security/CVE-2021-4090, https://bugzilla.redhat.com/show_bug.cgi?id=2025101, https://git.kernel.org/linus/c0019b7db1d7ac62c711cda6b357a659d46428fe, https://lore.kernel.org/linux-nfs/[email protected]/, https://ubuntu.com/security/notices/USN-5217-1, https://ubuntu.com/security/notices/USN-5265-1, https://ubuntu.com/security/notices/USN-5362-1, https://www.cve.org/CVERecord?id=CVE-2021-4090

    Affected packages

    Package

    Name: linux-hwe-edge

    Purl: pkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=xenial

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -None

    Affected versions

    4.8.0-28.30~16.04.1
    4.8.0-30.32~16.04.1
    4.8.0-32.34~16.04.1
    4.8.0-34.36~16.04.1

    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-2021-4090 | CVE-DB