UBUNTU-CVE-2021-20237

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    UBUNTU-CVE-2021-20237

    Published: 28 May 2021Last Modified: 22 Apr 2026
    Upstream:
    CVE-2021-20237
    Aliases:
    USN-4920-1

    Summary:

    Details: An uncontrolled resource consumption (memory leak) flaw was found in ZeroMQ's src/xpub.cpp in versions before 4.3.3. This flaw allows a remote unauthenticated attacker to send crafted PUB messages that consume excessive memory if the CURVE/ZAP authentication is disabled on the server, causing a denial of service. The highest threat from this vulnerability is to system availability.

    References: https://ubuntu.com/security/CVE-2021-20237, https://github.com/zeromq/libzmq/security/advisories/GHSA-4p5v-h92w-6wxw, https://ubuntu.com/security/notices/USN-4920-1, https://www.cve.org/CVERecord?id=CVE-2021-20237

    Affected packages

    Package

    Name: zeromq3

    Purl: pkg:deb/ubuntu/[email protected]+esm2?arch=source&distro=esm-apps/bionic

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -4.2.5-1ubuntu0.2+esm2

    Affected versions

    4.2.1-4ubuntu1
    4.2.2-1ubuntu2
    4.2.3-1
    4.2.3-1build1
    4.2.5-1
    4.2.5-1ubuntu0.1
    4.2.5-1ubuntu0.2
    4.2.5-1ubuntu0.2+esm1

    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-2021-20237 | CVE-DB