UBUNTU-CVE-2021-33200

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    UBUNTU-CVE-2021-33200

    Published: 27 May 2021Last Modified: 4 Feb 2026
    Upstream:
    CVE-2021-33200
    Aliases:
    USN-4983-1
    USN-4997-1
    USN-4997-2

    Summary:

    Details: kernel/bpf/verifier.c in the Linux kernel through 5.12.7 enforces incorrect limits for pointer arithmetic operations, aka CID-bb01a1bba579. This can be abused to perform out-of-bounds reads and writes in kernel memory, leading to local privilege escalation to root. In particular, there is a corner case where the off reg causes a masking direction change, which then results in an incorrect final aux->alu_limit.

    References: https://ubuntu.com/security/CVE-2021-33200, https://www.openwall.com/lists/oss-security/2021/05/27/1, https://ubuntu.com/security/notices/USN-4983-1, https://ubuntu.com/security/notices/USN-4997-1, https://ubuntu.com/security/notices/USN-4999-1, https://ubuntu.com/security/notices/USN-5000-1, https://ubuntu.com/security/notices/USN-5018-1, https://ubuntu.com/security/notices/USN-5000-2, https://ubuntu.com/security/notices/USN-4997-2, https://www.cve.org/CVERecord?id=CVE-2021-33200

    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-2021-33200 | CVE-DB