UBUNTU-CVE-2021-20194

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    UBUNTU-CVE-2021-20194

    Published: 23 Feb 2021Last Modified: 9 Sept 2026
    Upstream:
    CVE-2021-20194
    Aliases:
    USN-4879-1
    USN-4884-1
    USN-4909-1

    Summary:

    Details: There is a vulnerability in the linux kernel versions higher than 5.2 (if kernel compiled with config params CONFIG_BPF_SYSCALL=y , CONFIG_BPF=y , CONFIG_CGROUPS=y , CONFIG_CGROUP_BPF=y , CONFIG_HARDENED_USERCOPY not set, and BPF hook to getsockopt is registered). As result of BPF execution, the local user can trigger bug in __cgroup_bpf_run_filter_getsockopt() function that can lead to heap overflow (because of non-hardened usercopy). The impact of attack could be deny of service or possibly privileges escalation.

    References: https://ubuntu.com/security/CVE-2021-20194, https://bugzilla.redhat.com/show_bug.cgi?id=1912683, https://patchwork.kernel.org/project/netdevbpf/patch/[email protected]/#23921223, https://ubuntu.com/security/notices/USN-4879-1, https://ubuntu.com/security/notices/USN-4884-1, https://ubuntu.com/security/notices/USN-4909-1, https://ubuntu.com/security/notices/USN-4912-1, https://www.cve.org/CVERecord?id=CVE-2021-20194

    Affected packages

    Package

    Name: linux-hwe-edge

    Purl: pkg:deb/ubuntu/linux-hwe-edge?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-2021-20194 | CVE-DB