UBUNTU-CVE-2021-3975

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    UBUNTU-CVE-2021-3975

    Published: 24 Nov 2021Last Modified: 15 Aug 2026
    Upstream:
    CVE-2021-3975
    Aliases:
    USN-5399-1

    Summary:

    Details: A use-after-free flaw was found in libvirt. The qemuMonitorUnregister() function in qemuProcessHandleMonitorEOF is called using multiple threads without being adequately protected by a monitor lock. This flaw could be triggered by the virConnectGetAllDomainStats API when the guest is shutting down. An unprivileged client with a read-only connection could use this flaw to perform a denial of service attack by causing the libvirt daemon to crash.

    References: https://ubuntu.com/security/CVE-2021-3975, https://ubuntu.com/security/notices/USN-5399-1, https://www.cve.org/CVERecord?id=CVE-2021-3975

    Affected packages

    Package

    Name: libvirt

    Purl: pkg:deb/ubuntu/libvirt?arch=source&distro=bionic

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -4.0.0-1ubuntu8.21

    Affected versions

    3.6.0-1ubuntu5
    3.6.0-1ubuntu6

    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-2021-3975 | CVE-DB